diff --git a/apps/remix-ide-e2e/src/commands/verifyContracts.ts b/apps/remix-ide-e2e/src/commands/verifyContracts.ts
index aef1b06217..f29c3e42c6 100644
--- a/apps/remix-ide-e2e/src/commands/verifyContracts.ts
+++ b/apps/remix-ide-e2e/src/commands/verifyContracts.ts
@@ -2,7 +2,7 @@ import { NightwatchBrowser } from 'nightwatch'
 import EventEmitter from 'events'
 
 class VerifyContracts extends EventEmitter {
-  command (this: NightwatchBrowser, compiledContractNames: string[], opts = { wait: 1000, version: null }): NightwatchBrowser {
+  command (this: NightwatchBrowser, compiledContractNames: string[], opts = { wait: 1000, version: null, runs: '200' }): NightwatchBrowser {
     this.api.perform((done) => {
       verifyContracts(this.api, compiledContractNames, opts, () => {
         done()
@@ -13,13 +13,13 @@ class VerifyContracts extends EventEmitter {
   }
 }
 
-function verifyContracts (browser: NightwatchBrowser, compiledContractNames: string[], opts: { wait: number, version?: string }, callback: VoidFunction) {
+function verifyContracts (browser: NightwatchBrowser, compiledContractNames: string[], opts: { wait: number, version?: string, runs?: string }, callback: VoidFunction) {
   browser
     .clickLaunchIcon('solidity')
     .pause(opts.wait)
     .pause(5000)
     .waitForElementPresent('*[data-id="compiledContracts"] option', 60000)
-    .perform((done) => {
+    .perform(async (done) => {
       if (opts.version) {
         browser
           .click('*[data-id="compilation-details"]')
@@ -36,10 +36,28 @@ function verifyContracts (browser: NightwatchBrowser, compiledContractNames: str
             done()
             callback()
           })
-      } else {
-        compiledContractNames.forEach((name) => {
-          browser.waitForElementContainsText('[data-id="compiledContracts"]', name, 60000)
+      } if (opts.runs) {
+        browser
+        .click('*[data-id="compilation-details"]')
+        .waitForElementVisible('*[data-id="remixui_treeviewitem_metadata"]')
+        .pause(2000)
+        .click('*[data-id="remixui_treeviewitem_metadata"]')
+        .waitForElementVisible('*[data-id="treeViewDivtreeViewItemsettings"]')
+        .pause(2000)
+        .click('*[data-id="treeViewDivtreeViewItemsettings"]')
+        .waitForElementVisible('*[data-id="treeViewDivtreeViewItemoptimizer"]')
+        .click('*[data-id="treeViewDivtreeViewItemoptimizer"]')
+        .waitForElementVisible('*[data-id="treeViewDivruns"]')
+        .assert.containsText('*[data-id="treeViewDivruns"]', `${opts.runs}`)
+        .click('[data-id="workspacesModalDialog-modal-footer-ok-react"]')
+        .perform(() => {
+          done()
+          callback()
         })
+      } else {
+        for (const index in compiledContractNames) {
+         await browser.waitForElementContainsText('[data-id="compiledContracts"]', compiledContractNames[index], 60000)
+        }
         done()
         callback()
       }
diff --git a/apps/remix-ide-e2e/src/tests/ballot.test.ts b/apps/remix-ide-e2e/src/tests/ballot.test.ts
index 794dee9775..5244241e89 100644
--- a/apps/remix-ide-e2e/src/tests/ballot.test.ts
+++ b/apps/remix-ide-e2e/src/tests/ballot.test.ts
@@ -122,6 +122,24 @@ module.exports = {
         })
       // Test in Udapp UI , treeViewDiv0 shows returned value on method click
       .assert.containsText('*[data-id="treeViewDiv0"]', 'bytes32: winnerName_ 0x48656c6c6f20576f726c64210000000000000000000000000000000000000000')
+  },
+
+  'Compile Ballot using config file': function (browser: NightwatchBrowser) {
+    browser
+      .addFile('cf.json', {content: configFile})
+      .clickLaunchIcon('solidity')
+      .waitForElementVisible('*[data-id="scConfigExpander"]')
+      .click('*[data-id="scConfigExpander"]')
+      .waitForElementVisible('*[data-id="scFileConfiguration"]', 10000)
+      .click('*[data-id="scFileConfiguration"]')
+      .waitForElementVisible('*[data-id="scConfigChangeFilePath"]', 10000)
+      .click('*[data-id="scConfigChangeFilePath"]')
+      .waitForElementVisible('*[data-id="scConfigFilePathInput"]', 10000)
+      .clearValue('*[data-id="scConfigFilePathInput"]')
+      .setValue('*[data-id="scConfigFilePathInput"]', 'cf.json')
+      .sendKeys('*[data-id$="scConfigFilePathInput"]', browser.Keys.ENTER)
+      .openFile('Untitled.sol')
+      .verifyContracts(['Ballot'], {wait: 2000, runs: '300'})
       .end()
   }
 }
@@ -190,6 +208,7 @@ const stateCheck = {
     immutable: false
   }
 }
+
 const ballotABI = `[
 {
   "inputs": [
@@ -356,3 +375,22 @@ const ballotABI = `[
   "type": "function"
 }
 ]`
+
+const configFile = `
+{
+	"language": "Solidity",
+	"settings": {
+		"optimizer": {
+			"enabled": true,
+			"runs": 300
+		},
+		"outputSelection": {
+			"*": {
+			"": ["ast"],
+      "*": ["abi", "metadata", "devdoc", "userdoc", "storageLayout", "evm.legacyAssembly", "evm.bytecode", "evm.deployedBytecode", "evm.methodIdentifiers", "evm.gasEstimates", "evm.assembly"]
+			}
+		},
+		"evmVersion": "byzantium"
+	}
+}
+`
\ No newline at end of file
diff --git a/apps/remix-ide-e2e/src/tests/compiler_api.test.ts b/apps/remix-ide-e2e/src/tests/compiler_api.test.ts
index 2adc5a4c62..0646b83f80 100644
--- a/apps/remix-ide-e2e/src/tests/compiler_api.test.ts
+++ b/apps/remix-ide-e2e/src/tests/compiler_api.test.ts
@@ -168,3 +168,4 @@ contract DoesNotCompile {
     function fStackLimit(uint u1, uint u2, uint u3, uint u4, uint u5, uint u6, uint u7, uint u8, uint u9, uint u10, uint u11, uint u12) public {        
     }
 }`
+
diff --git a/apps/remix-ide-e2e/src/tests/plugin_api.ts b/apps/remix-ide-e2e/src/tests/plugin_api.ts
index cf696f2bec..faabf03247 100644
--- a/apps/remix-ide-e2e/src/tests/plugin_api.ts
+++ b/apps/remix-ide-e2e/src/tests/plugin_api.ts
@@ -231,7 +231,6 @@ module.exports = {
 
   'Should get current files #group7': async function (browser: NightwatchBrowser) {
     await clickAndCheckLog(browser, 'fileManager:readdir', {
-      'compiler_config.json': { isDirectory: false },
       contracts: { isDirectory: true },
       scripts: { isDirectory: true },
       tests: { isDirectory: true },
@@ -286,15 +285,12 @@ module.exports = {
   'Should create empty workspace #group2': async function (browser: NightwatchBrowser) {
     await clickAndCheckLog(browser, 'filePanel:createWorkspace', null, null, ['emptyworkspace', true])
     await clickAndCheckLog(browser, 'filePanel:getCurrentWorkspace', { name: 'emptyworkspace', isLocalhost: false, absolutePath: '.workspaces/emptyworkspace' }, null, null)
-    await clickAndCheckLog(browser, 'fileManager:readdir', {
-      'compiler_config.json': { isDirectory: false }
-    }, null, '/')
+    await clickAndCheckLog(browser, 'fileManager:readdir', {}, null, '/')
   },
   'Should create workspace #group2': async function (browser: NightwatchBrowser) {
     await clickAndCheckLog(browser, 'filePanel:createWorkspace', null, null, 'testspace')
     await clickAndCheckLog(browser, 'filePanel:getCurrentWorkspace', { name: 'testspace', isLocalhost: false, absolutePath: '.workspaces/testspace' }, null, null)
     await clickAndCheckLog(browser, 'fileManager:readdir', {
-      'compiler_config.json': { isDirectory: false },
       contracts: { isDirectory: true },
       scripts: { isDirectory: true },
       tests: { isDirectory: true },
diff --git a/apps/remix-ide-e2e/src/tests/workspace.test.ts b/apps/remix-ide-e2e/src/tests/workspace.test.ts
index f5fea02e36..0c36951a76 100644
--- a/apps/remix-ide-e2e/src/tests/workspace.test.ts
+++ b/apps/remix-ide-e2e/src/tests/workspace.test.ts
@@ -107,8 +107,7 @@ module.exports = {
         const fileList = document.querySelector('*[data-id="treeViewUltreeViewMenu"]')
         return fileList.getElementsByTagName('li').length;
       }, [], function(result){
-          // check there are no files in FE except config file
-          browser.assert.equal(result.value, 1, 'Incorrect number of files');
+          browser.assert.equal(result.value, 0, 'Incorrect number of files');
       });
   },
 
diff --git a/apps/remix-ide-e2e/src/types/index.d.ts b/apps/remix-ide-e2e/src/types/index.d.ts
index e8698d4407..7fbcb174d5 100644
--- a/apps/remix-ide-e2e/src/types/index.d.ts
+++ b/apps/remix-ide-e2e/src/types/index.d.ts
@@ -11,7 +11,7 @@ declare module 'nightwatch' {
         testContracts(fileName: string, contractCode: NightwatchContractContent, compiledContractNames: string[]): NightwatchBrowser,
         setEditorValue(value: string, callback?: () => void): NightwatchBrowser,
         addFile(name: string, content: NightwatchContractContent): NightwatchBrowser,
-        verifyContracts(compiledContractNames: string[], opts?: { wait: number, version?: string }): NightwatchBrowser,
+        verifyContracts(compiledContractNames: string[], opts?: { wait: number, version?: string, runs?: string }): NightwatchBrowser,
         selectAccount(account?: string): NightwatchBrowser,
         clickFunction(fnFullName: string, expectedInput?: NightwatchClickFunctionExpectedInput): NightwatchBrowser,
         testFunction(txHash: string, expectedInput: NightwatchTestFunctionExpectedInput): NightwatchBrowser,
diff --git a/apps/remix-ide/src/app/editor/editor.js b/apps/remix-ide/src/app/editor/editor.js
index 50f7f42d76..97dc63f988 100644
--- a/apps/remix-ide/src/app/editor/editor.js
+++ b/apps/remix-ide/src/app/editor/editor.js
@@ -167,6 +167,32 @@ class Editor extends Plugin {
       }
     })
 
+    this.on('fileManager', 'noFileSelected', async () => {
+      this.currentFile = null
+      this.renderComponent()
+    })
+    this.on('fileManager', 'currentFileChanged', async (name) => {
+      if (name.endsWith('.ts')) {
+        // extract the import, resolve their content
+        // and add the imported files to Monaco through the `addModel`
+        // so Monaco can provide auto completion
+        let content = await this.call('fileManager', 'readFile', name)
+        const paths = name.split('/')
+        paths.pop()
+        const fromPath = paths.join('/') // get current execution context path
+        for (const match of content.matchAll(/import\s+.*\s+from\s+(?:"(.*?)"|'(.*?)')/g)) {
+          let path = match[2]
+          if (path.startsWith('./') || path.startsWith('../')) path = resolve(fromPath, path)
+          if (path.startsWith('/')) path = path.substring(1)
+          if (!path.endsWith('.ts')) path = path + '.ts'
+          if (await this.call('fileManager', 'exists', path)) {
+            content = await this.call('fileManager', 'readFile', path)
+            this.emit('addModel', content, 'typescript', path, false)
+          }
+        }
+      }
+    })
+
     this.on('fileManager', 'noFileSelected', async () => {
       this.currentFile = null
       this.renderComponent()
diff --git a/apps/remix-ide/src/app/tabs/compile-tab.js b/apps/remix-ide/src/app/tabs/compile-tab.js
index 8e3d17e366..23a53846f7 100644
--- a/apps/remix-ide/src/app/tabs/compile-tab.js
+++ b/apps/remix-ide/src/app/tabs/compile-tab.js
@@ -56,6 +56,10 @@ class CompileTab extends CompilerApiMixin(ViewPlugin) { // implements ICompilerA
     this.renderComponent()
   }
 
+  onFileRemoved () {
+    this.renderComponent()
+  }
+
   onNoFileSelected () {
     this.renderComponent()
   }
diff --git a/apps/solidity-compiler/src/app/compiler-api.ts b/apps/solidity-compiler/src/app/compiler-api.ts
index fb8d848039..3065af630a 100644
--- a/apps/solidity-compiler/src/app/compiler-api.ts
+++ b/apps/solidity-compiler/src/app/compiler-api.ts
@@ -19,6 +19,7 @@ export const CompilerApiMixin = (Base) => class extends Base {
   onCurrentFileChanged: (fileName: string) => void
   // onResetResults: () => void
   onSetWorkspace: (isLocalhost: boolean, workspaceName: string) => void
+  onFileRemoved: (path: string) => void
   onNoFileSelected: () => void
   onCompilationFinished: (compilationDetails: { contractMap: { file: string } | Record<string, any>, contractsDetails: Record<string, any> }) => void
   onSessionSwitched: () => void
@@ -240,6 +241,10 @@ export const CompilerApiMixin = (Base) => class extends Base {
       if (this.onSetWorkspace) this.onSetWorkspace(workspace.isLocalhost, workspace.name)
     })
 
+    this.on('fileManager', 'fileRemoved', (path) => {
+      if (this.onFileRemoved) this.onFileRemoved(path)
+    })
+
     this.on('remixd', 'rootFolderChanged', () => {
       this.resetResults()
       if (this.onSetWorkspace) this.onSetWorkspace(true, 'localhost')
@@ -282,23 +287,20 @@ export const CompilerApiMixin = (Base) => class extends Base {
             type: 'warning'
           })
         } else this.statusChanged({ key: 'succeed', title: 'compilation successful', type: 'success' })
-        // Store the contracts
-        this.compilationDetails.contractsDetails = {}
-        this.compiler.visitContracts((contract) => {
-          this.compilationDetails.contractsDetails[contract.name] = parseContracts(
-            contract.name,
-            contract.object,
-            this.compiler.getSource(contract.file)
-          )
-        })
       } else {
         const count = (data.errors ? data.errors.filter(error => error.severity === 'error').length : 0 + (data.error ? 1 : 0))
         this.statusChanged({ key: count, title: `compilation failed with ${count} error${count > 1 ? 's' : ''}`, type: 'error' })
       }
-      // Update contract Selection
-      this.compilationDetails.contractMap = {}
-      if (success) this.compiler.visitContracts((contract) => { this.compilationDetails.contractMap[contract.name] = contract })
-      this.compilationDetails.target = source.target
+      // Store the contracts and Update contract Selection
+      if (success) {
+        this.compilationDetails = await this.visitsContractApi(source, data)
+      } else {
+        this.compilationDetails = {
+          contractMap: {},
+          contractsDetails: {},
+          target: source.target
+        }
+      }
       if (this.onCompilationFinished) this.onCompilationFinished(this.compilationDetails)
       // set annotations
       if (data.errors) {
@@ -342,4 +344,31 @@ export const CompilerApiMixin = (Base) => class extends Base {
     }
     window.document.addEventListener('keydown', this.data.eventHandlers.onKeyDown)
   }
+
+  async visitsContractApi (source, data): Promise<{ contractMap: { file: string } | Record<string, any>, contractsDetails: Record<string, any>, target?: string }> {
+    return new Promise((resolve) => {
+      if (!data.contracts || (data.contracts && Object.keys(data.contracts).length === 0)) {
+        return resolve({
+          contractMap: {}, 
+          contractsDetails: {},
+          target: source.target
+        })
+      }
+      const contractMap = {}
+      const contractsDetails = {}
+      this.compiler.visitContracts((contract) => {
+        contractMap[contract.name] = contract
+        contractsDetails[contract.name] = parseContracts(
+          contract.name,
+          contract.object,
+          this.compiler.getSource(contract.file)
+        )
+      })
+      return resolve({
+        contractMap, 
+        contractsDetails,
+        target: source.target
+      })
+    })
+  }
 }
diff --git a/libs/remix-lib/src/types/ICompilerApi.ts b/libs/remix-lib/src/types/ICompilerApi.ts
index f34d20f420..259aa2547a 100644
--- a/libs/remix-lib/src/types/ICompilerApi.ts
+++ b/libs/remix-lib/src/types/ICompilerApi.ts
@@ -25,6 +25,7 @@ export interface ICompilerApi {
     onCurrentFileChanged: (fileName: string) => void
     // onResetResults: () => void,
     onSetWorkspace: (isLocalhost: boolean, workspaceName: string) => void
+    onFileRemoved: (path: string) => void
     onNoFileSelected: () => void
     onCompilationFinished: (contractsDetails: any, contractMap: any) => void
     onSessionSwitched: () => void
diff --git a/libs/remix-ui/editor/src/lib/remix-plugin-types.ts b/libs/remix-ui/editor/src/lib/remix-plugin-types.ts
index ef781936c0..ceb49f5399 100644
--- a/libs/remix-ui/editor/src/lib/remix-plugin-types.ts
+++ b/libs/remix-ui/editor/src/lib/remix-plugin-types.ts
@@ -226,7 +226,7 @@ declare interface CondensedCompilationInput {
     optimize: boolean
     /** e.g: 0.6.8+commit.0bbfe453 */
     version: string
-    evmVersion?: 'istanbul' | 'petersburg' | 'constantinople' | 'byzantium' | 'spuriousDragon' | 'tangerineWhistle' | 'homestead'
+    evmVersion?: 'berlin' | 'istanbul' | 'petersburg' | 'constantinople' | 'byzantium' | 'spuriousDragon' | 'tangerineWhistle' | 'homestead'
 }
 
 declare interface ContentImport {
diff --git a/libs/remix-ui/solidity-compiler/src/lib/compiler-container.tsx b/libs/remix-ui/solidity-compiler/src/lib/compiler-container.tsx
index 17d3baa2d2..bc06aae822 100644
--- a/libs/remix-ui/solidity-compiler/src/lib/compiler-container.tsx
+++ b/libs/remix-ui/solidity-compiler/src/lib/compiler-container.tsx
@@ -12,6 +12,7 @@ import { CopyToClipboard } from '@remix-ui/clipboard'
 import { configFileContent } from './compilerConfiguration'
 
 import './css/style.css'
+const defaultPath = "compiler_config.json"
 
 declare global {
   interface Window {
@@ -22,11 +23,23 @@ declare global {
 const _paq = window._paq = window._paq || [] //eslint-disable-line
 
 export const CompilerContainer = (props: CompilerContainerProps) => {
-  const { api, compileTabLogic, tooltip, modal, compiledFileName, updateCurrentVersion, configurationSettings, isHardhatProject, isTruffleProject, workspaceName } = props // eslint-disable-line
+  const {
+    api,
+    compileTabLogic,
+    tooltip,
+    modal,
+    compiledFileName,
+    updateCurrentVersion,
+    configurationSettings,
+    isHardhatProject,
+    isTruffleProject,
+    workspaceName,
+    configFilePath,
+    setConfigFilePath,
+  } = props // eslint-disable-line
   const [state, setState] = useState({
     hideWarnings: false,
     autoCompile: false,
-    configFilePath: "compiler_config.json",
     useFileConfiguration: false,
     matomoAutocompileOnce: true,
     optimize: false,
@@ -40,7 +53,8 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
     compiledFileName: '',
     includeNightlies: false,
     language: 'Solidity',
-    evmVersion: ''
+    evmVersion: '',
+    createFileOnce: true
   })
   const [showFilePathInput, setShowFilePathInput] = useState<boolean>(false)
   const [toggleExpander, setToggleExpander] = useState<boolean>(false)
@@ -53,17 +67,27 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
   const [compilerContainer, dispatch] = useReducer(compilerReducer, compilerInitialState)
 
   useEffect(() => {
-    api.setAppParameter('configFilePath', "/compiler_config.json")
-    api.fileExists("/compiler_config.json").then((exists) => {
-      if (!exists) createNewConfigFile()
-      else {
-        // what to do? discuss
+    if (workspaceName) {
+      api.setAppParameter('configFilePath', defaultPath)
+      if (state.useFileConfiguration) {
+        api.fileExists(defaultPath).then((exists) => {
+          if (!exists && state.useFileConfiguration) createNewConfigFile()
+        })
       }
-    })
-    api.setAppParameter('configFilePath', "/compiler_config.json")
-    setShowFilePathInput(false)
+      setShowFilePathInput(false)
+    }
   }, [workspaceName])
 
+  useEffect(() => {
+    if (state.useFileConfiguration) {
+      api.fileExists(defaultPath).then((exists) => {
+        if (!exists) createNewConfigFile()
+      })
+      setToggleExpander(true)
+    }
+  }, [state.useFileConfiguration])
+
+
   useEffect(() => {
     const listener = (event) => {
       if (configFilePathInput.current !== event.target) {
@@ -106,8 +130,10 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
         const hideWarnings = await api.getAppParameter('hideWarnings') as boolean || false
         const includeNightlies = await api.getAppParameter('includeNightlies') as boolean || false
         const useFileConfiguration = await api.getAppParameter('useFileConfiguration') as boolean || false
-        let configFilePath = await api.getAppParameter('configFilePath')
-        if (!configFilePath || configFilePath == '') configFilePath = "/compiler_config.json"
+        let configFilePathSaved = await api.getAppParameter('configFilePath')
+        if (!configFilePathSaved || configFilePathSaved == '') configFilePathSaved = defaultPath
+
+        setConfigFilePath(configFilePathSaved)
 
         setState(prevState => {
           const params = api.getCompilerParameters()
@@ -122,7 +148,6 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
             autoCompile: autocompile,
             includeNightlies: includeNightlies,
             useFileConfiguration: useFileConfiguration,
-            configFilePath: configFilePath,
             optimize: optimize,
             runs: runs,
             evmVersion: (evmVersion !== null) && (evmVersion !== 'null') && (evmVersion !== undefined) && (evmVersion !== 'undefined') ? evmVersion : 'default',
@@ -181,7 +206,7 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
 
   useEffect(() => {
     compileTabLogic.setUseFileConfiguration(state.useFileConfiguration)
-    if (state.useFileConfiguration) compileTabLogic.setConfigFilePath(state.configFilePath)
+    if (state.useFileConfiguration) compileTabLogic.setConfigFilePath(configFilePath)
   }, [state.useFileConfiguration])
 
   useEffect(() => {
@@ -191,6 +216,16 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
   }, [configurationSettings])
 
   const toggleConfigType = () => {
+    if (state.useFileConfiguration)
+      if (state.createFileOnce) {
+        api.fileExists(defaultPath).then((exists) => {
+          if (!exists || state.useFileConfiguration ) createNewConfigFile()
+        })
+        setState(prevState => {
+          return { ...prevState, createFileOnce: false }
+        })
+      }
+    
     setState(prevState => {
       api.setAppParameter('useFileConfiguration', !state.useFileConfiguration)
       return { ...prevState, useFileConfiguration: !state.useFileConfiguration }
@@ -198,18 +233,17 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
   }
 
   const openFile = async () => {
-    api.open(state.configFilePath)
+    api.open(configFilePath)
   }
 
   const createNewConfigFile = async () => {
-    let filePath = configFilePathInput.current && configFilePathInput.current.value !== '' ? configFilePathInput.current.value : state.configFilePath
+    let filePath = configFilePathInput.current && configFilePathInput.current.value !== '' ? configFilePathInput.current.value : configFilePath
+    if (filePath === '') filePath = defaultPath
     if (!filePath.endsWith('.json')) filePath = filePath + '.json'
 
     await api.writeFile(filePath, configFileContent)
     api.setAppParameter('configFilePath', filePath)
-    setState(prevState => {
-      return { ...prevState, configFilePath: filePath }
-    })
+    setConfigFilePath(filePath)
     compileTabLogic.setConfigFilePath(filePath)
     setShowFilePathInput(false)
   }
@@ -220,9 +254,7 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
 
       if (await api.fileExists(configFilePathInput.current.value)) {
         api.setAppParameter('configFilePath', configFilePathInput.current.value)
-        setState(prevState => {
-          return { ...prevState, configFilePath: configFilePathInput.current.value }
-        })
+        setConfigFilePath(configFilePathInput.current.value)
         compileTabLogic.setConfigFilePath(configFilePathInput.current.value)
 
         setShowFilePathInput(false)
@@ -394,6 +426,9 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
     compileIcon.current.classList.remove('remixui_spinningIcon')
     compileIcon.current.classList.remove('remixui_bouncingIcon')
     if (!state.autoCompile || (state.autoCompile && state.matomoAutocompileOnce)) {
+      if (state.useFileConfiguration)
+        _paq.push(['trackEvent', 'compiler', 'compiled_with_config_file'])
+
       _paq.push(['trackEvent', 'compiler', 'compiled_with_version', _retrieveVersion()])
       if (state.autoCompile && state.matomoAutocompileOnce) {
         setState(prevState => {
@@ -750,36 +785,38 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
           </div>
           <div className="d-flex pb-1 remixui_compilerConfig custom-control custom-radio">
             <input className="custom-control-input" type="radio" name="configradio" value="file" onChange={toggleConfigType} checked={state.useFileConfiguration} id="scFileConfig" />
-            <label className="form-check-label custom-control-label" htmlFor="scFileConfig">Use configuration file</label>
+            <label className="form-check-label custom-control-label" htmlFor="scFileConfig" data-id="scFileConfiguration">Use configuration file</label>
           </div>
           <div className={`pt-2 ml-4 ml-2 align-items-start justify-content-between d-flex`}>
             { (!showFilePathInput && state.useFileConfiguration) && <span
               title="Click to open the config file."
-              onClick={openFile}
-              className="py-2 text-primary remixui_compilerConfigPath"
-            >{state.configFilePath}</span> }
-            { (!showFilePathInput&& !state.useFileConfiguration) && <span className="py-2 text-secondary">{state.configFilePath}</span> }
+              onClick={configFilePath === '' ? () => {} : openFile}
+              className="py-2 remixui_compilerConfigPath"
+            >{configFilePath === '' ? 'No file selected.' : configFilePath}</span> }
+            { (!showFilePathInput && !state.useFileConfiguration) && <span className="py-2 text-secondary">{configFilePath}</span> }
             <input
               ref={configFilePathInput}
               className={`py-0 my-0 form-control ${showFilePathInput ? "d-flex" : "d-none"}`}
               placeholder={"Enter the new path"}
               title="If the file you entered does not exist you will be able to create one in the next step."
               disabled={!state.useFileConfiguration}
+              data-id="scConfigFilePathInput"
               onKeyPress={event => {
                 if (event.key === 'Enter') {
                   handleConfigPathChange()
                 }
               }}
             />
-            { !showFilePathInput && <button disabled={!state.useFileConfiguration} className="btn-secondary" onClick={() => {setShowFilePathInput(true)}}>Change</button> }
+            { !showFilePathInput && <button disabled={!state.useFileConfiguration} data-id="scConfigChangeFilePath" className="btn-secondary" onClick={() => {setShowFilePathInput(true)}}>Change</button> }
           </div>
         </div>
         <div className="px-4">
-          <button id="compileBtn" data-id="compilerContainerCompileBtn" className="btn btn-primary btn-block d-block w-100 text-break remixui_disabled mb-1 mt-3" onClick={compile} disabled={disableCompileButton}>
+          <button id="compileBtn" data-id="compilerContainerCompileBtn" className="btn btn-primary btn-block d-block w-100 text-break remixui_disabled mb-1 mt-3" onClick={compile} disabled={(configFilePath === '' && state.useFileConfiguration) || disableCompileButton}>
             <OverlayTrigger overlay={
               <Tooltip id="overlay-tooltip-compile">
                 <div className="text-left">
-                  <div><b>Ctrl+S</b> for compiling</div>
+                  { !(configFilePath === '' && state.useFileConfiguration) && <div><b>Ctrl+S</b> for compiling</div> }
+                  { (configFilePath === '' && state.useFileConfiguration) && <div> No config file selected</div> }
                 </div>
               </Tooltip>
             }>
@@ -790,11 +827,12 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
             </OverlayTrigger>
           </button>
           <div className='d-flex align-items-center'>            
-            <button id="compileAndRunBtn" data-id="compilerContainerCompileAndRunBtn" className="btn btn-secondary btn-block d-block w-100 text-break remixui_solidityCompileAndRunButton d-inline-block remixui_disabled mb-1 mt-3" onClick={compileAndRun} disabled={disableCompileButton}>
+            <button id="compileAndRunBtn" data-id="compilerContainerCompileAndRunBtn" className="btn btn-secondary btn-block d-block w-100 text-break remixui_solidityCompileAndRunButton d-inline-block remixui_disabled mb-1 mt-3" onClick={compileAndRun} disabled={(configFilePath === '' && state.useFileConfiguration) || disableCompileButton}>
               <OverlayTrigger overlay={
                 <Tooltip id="overlay-tooltip-compile-run">
                   <div className="text-left">
-                  <div><b>Ctrl+Shift+S</b> for compiling and script execution</div>
+                    { !(configFilePath === '' && state.useFileConfiguration) && <div><b>Ctrl+Shift+S</b> for compiling and script execution</div> }
+                    { (configFilePath === '' && state.useFileConfiguration) && <div> No config file selected</div> }
                   </div>
                 </Tooltip>
               }>
@@ -806,18 +844,18 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
             <OverlayTrigger overlay={
               <Tooltip id="overlay-tooltip-compile-run-doc">
                 <div className="text-left p-2">
-                <div>Choose the script to execute right after compilation by adding the `dev-run-script` natspec tag, as in:</div>
-                <pre>
-                  <code>
-                  /**<br />
-                  * @title ContractName<br />
-                  * @dev ContractDescription<br />
-                  * @custom:dev-run-script file_path<br />
-                  */<br />
-                  contract ContractName {'{}'}<br />
-                  </code>
-                </pre>
-                Click to know more
+                  <div>Choose the script to execute right after compilation by adding the `dev-run-script` natspec tag, as in:</div>
+                  <pre>
+                    <code>
+                    /**<br />
+                    * @title ContractName<br />
+                    * @dev ContractDescription<br />
+                    * @custom:dev-run-script file_path<br />
+                    */<br />
+                    contract ContractName {'{}'}<br />
+                    </code>
+                  </pre>
+                  Click to know more
                 </div>
               </Tooltip>
             }>
diff --git a/libs/remix-ui/solidity-compiler/src/lib/logic/compileTabLogic.ts b/libs/remix-ui/solidity-compiler/src/lib/logic/compileTabLogic.ts
index e84f73a76c..7497a529ae 100644
--- a/libs/remix-ui/solidity-compiler/src/lib/logic/compileTabLogic.ts
+++ b/libs/remix-ui/solidity-compiler/src/lib/logic/compileTabLogic.ts
@@ -24,7 +24,7 @@ export class CompileTabLogic {
   constructor (public api: ICompilerApi, public contentImport) {
     this.event = new EventEmitter()
     this.compiler = new Compiler((url, cb) => api.resolveContentAndSave(url).then((result) => cb(null, result)).catch((error) => cb(error.message)))
-    this.evmVersions = ['default', 'london', 'istanbul', 'petersburg', 'constantinople', 'byzantium', 'spuriousDragon', 'tangerineWhistle', 'homestead']
+    this.evmVersions = ['default', 'berlin', 'london', 'istanbul', 'petersburg', 'constantinople', 'byzantium', 'spuriousDragon', 'tangerineWhistle', 'homestead']
   }
 
   init () {
@@ -106,9 +106,11 @@ export class CompileTabLogic {
         const sources = { [target]: { content } }
         this.event.emit('removeAnnotations')
         this.event.emit('startingCompilation')
-        this.api.readFile(this.configFilePath).then( contentConfig => {
-          this.compiler.set('configFileContent', contentConfig)
-        })
+        if (this.configFilePath) {
+          this.api.readFile(this.configFilePath).then( contentConfig => {
+            this.compiler.set('configFileContent', contentConfig)
+          })
+        }
         // setTimeout fix the animation on chrome... (animation triggered by 'staringCompilation')
         setTimeout(() => { this.compiler.compile(sources, target); resolve(true) }, 100)
       }).catch((error) => {
diff --git a/libs/remix-ui/solidity-compiler/src/lib/solidity-compiler.tsx b/libs/remix-ui/solidity-compiler/src/lib/solidity-compiler.tsx
index 33d56f3175..827dea9f3f 100644
--- a/libs/remix-ui/solidity-compiler/src/lib/solidity-compiler.tsx
+++ b/libs/remix-ui/solidity-compiler/src/lib/solidity-compiler.tsx
@@ -15,6 +15,7 @@ export const SolidityCompiler = (props: SolidityCompilerProps) => {
     isTruffleProject: false,
     workspaceName: '',
     currentFile,
+    configFilePath: 'compiler_config.json',
     loading: false,
     compileTabLogic: null,
     compiler: null,
@@ -71,6 +72,13 @@ export const SolidityCompiler = (props: SolidityCompilerProps) => {
       return { ...prevState, currentFile, isHardhatProject: isHardhat, workspaceName: workspaceName, isTruffleProject:  isTruffle }
     })
   }
+  
+  api.onFileRemoved = (path: string) => {
+    if (path === state.configFilePath)
+      setState(prevState => {
+        return { ...prevState, configFilePath: '' }
+      })
+  }
 
   api.onNoFileSelected = () => {
     setState(prevState => {
@@ -103,6 +111,13 @@ export const SolidityCompiler = (props: SolidityCompilerProps) => {
     setBadgeStatus({ ...badgeStatus, [currentFile]: data })
   }
 
+  const setConfigFilePath = (path: string) => {
+    setState(prevState => {
+      return { ...prevState, configFilePath: path }
+    })
+  }
+
+
   const toast = (message: string) => {
     setState(prevState => {
       return { ...prevState, toasterMsg: message }
@@ -162,6 +177,8 @@ export const SolidityCompiler = (props: SolidityCompilerProps) => {
           compiledFileName={currentFile}
           updateCurrentVersion={updateCurrentVersion}
           configurationSettings={configurationSettings}
+          configFilePath={state.configFilePath}
+          setConfigFilePath={setConfigFilePath}
         />
         { contractsFile[currentFile] && contractsFile[currentFile].contractsDetails && <ContractSelection api={api} contractsDetails={contractsFile[currentFile].contractsDetails} contractList={contractsFile[currentFile].contractList} modal={modal} /> }
         { compileErrors[currentFile] &&
diff --git a/libs/remix-ui/solidity-compiler/src/lib/types/index.ts b/libs/remix-ui/solidity-compiler/src/lib/types/index.ts
index 37cffd4289..38f4edb61e 100644
--- a/libs/remix-ui/solidity-compiler/src/lib/types/index.ts
+++ b/libs/remix-ui/solidity-compiler/src/lib/types/index.ts
@@ -16,7 +16,9 @@ export interface CompilerContainerProps {
   modal: (title: string, message: string | JSX.Element, okLabel: string, okFn: () => void, cancelLabel?: string, cancelFn?: () => void) => void,
   compiledFileName: string,
   updateCurrentVersion: any,
-  configurationSettings: ConfigurationSettings
+  configurationSettings: ConfigurationSettings,
+  configFilePath: string,
+  setConfigFilePath: (path: string) => void
 }
 export interface ContractSelectionProps {
   api: ICompilerApi,
diff --git a/libs/remix-ui/workspace/src/lib/css/remix-ui-workspace.css b/libs/remix-ui/workspace/src/lib/css/remix-ui-workspace.css
index 354be77283..62a557f8cf 100644
--- a/libs/remix-ui/workspace/src/lib/css/remix-ui-workspace.css
+++ b/libs/remix-ui/workspace/src/lib/css/remix-ui-workspace.css
@@ -13,6 +13,7 @@
     padding-left      : 6px;
     padding-right     : 6px;
     padding-top       : 6px;
+    overflow-y        : auto;
   }
   .remixui_fileExplorerTree   {
     cursor            : default;
diff --git a/libs/remix-ui/workspace/src/lib/remix-ui-workspace.tsx b/libs/remix-ui/workspace/src/lib/remix-ui-workspace.tsx
index 9e0b0a0f04..2015c8d396 100644
--- a/libs/remix-ui/workspace/src/lib/remix-ui-workspace.tsx
+++ b/libs/remix-ui/workspace/src/lib/remix-ui-workspace.tsx
@@ -228,9 +228,9 @@ export function Workspace () {
             </div>
           </header>
         </div>
-        <div className='remixui_fileExplorerTree'>
-          <div>
-            <div className='pl-2 remixui_treeview' data-id='filePanelFileExplorerTree'>
+        <div className='h-100 remixui_fileExplorerTree'>
+          <div className='h-100'>
+            <div className='pl-2 h-100 remixui_treeview' data-id='filePanelFileExplorerTree'>
               { (global.fs.mode === 'browser') && (currentWorkspace !== NO_WORKSPACE) &&
                   <FileExplorer
                     name={currentWorkspace}
diff --git a/package.json b/package.json
index ec1788e7c2..17d92657a0 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,7 @@
     "minify": "uglifyjs --in-source-map inline --source-map-inline -c warnings=false",
     "build:production": "NODE_ENV=production nx build remix-ide --skip-nx-cache",
     "serve:production": "npx http-server ./dist/apps/remix-ide",
-    "select_test": "sh apps/remix-ide-e2e/src/select_tests.sh",
+    "select_test": "bash apps/remix-ide-e2e/src/select_tests.sh",
     "group_test": "yarn run build:e2e && nightwatch --config dist/apps/remix-ide-e2e/nightwatch.js dist/apps/remix-ide-e2e/src/tests/${npm_config_test}_group${npm_config_group}.test.js --env=${npm_config_env}",
     "nightwatch_parallel": "yarn run build:e2e && nightwatch --config dist/apps/remix-ide-e2e/nightwatch.js --env=chrome,firefox",
     "nightwatch_local_firefox": "yarn run build:e2e && nightwatch --config dist/apps/remix-ide-e2e/nightwatch.js --env=firefox",