diff --git a/.circleci/config.yml b/.circleci/config.yml
index a7cae9785e..9d0791cd7e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -105,6 +105,7 @@ jobs:
     steps:
       - checkout
       - run: npm install
+      - run: npm run downloadsolc_assets
       - run: npx nx build remix-ide --with-deps
       - run:
           name: Download Selenium
@@ -171,6 +172,7 @@ jobs:
     steps:
       - checkout
       - run: npm install
+      - run: npm run downloadsolc_assets
       - run: npx nx build remix-ide --with-deps
       - run:
           name: Download Selenium
diff --git a/apps/debugger/src/app/debugger-api.ts b/apps/debugger/src/app/debugger-api.ts
index 2b5a149d16..ae75599bec 100644
--- a/apps/debugger/src/app/debugger-api.ts
+++ b/apps/debugger/src/app/debugger-api.ts
@@ -62,6 +62,10 @@ export const DebuggerApiMixin = (Base) => class extends Base {
     this.onEditorContentChangedListener = listener
   }
 
+  onEnvChanged (listener) {
+    this.onEnvChangedListener = listener
+  }
+
   onDebugRequested (listener) {
     this.onDebugRequestedListener = listener
   }
@@ -126,6 +130,7 @@ export const DebuggerApiMixin = (Base) => class extends Base {
     this.on('editor', 'breakpointCleared', (fileName, row) => { if (this.onBreakpointClearedListener) this.onBreakpointClearedListener(fileName, row) })
     this.on('editor', 'breakpointAdded', (fileName, row) => { if (this.onBreakpointAddedListener) this.onBreakpointAddedListener(fileName, row) })
     this.on('editor', 'contentChanged', () => { if (this.onEditorContentChangedListener) this.onEditorContentChangedListener() })  
+    this.on('network', 'providerChanged', (provider) => { if (this.onEnvChangedListener) this.onEnvChangedListener(provider) })
   }
 
   onDeactivation () {
diff --git a/apps/debugger/src/app/debugger.ts b/apps/debugger/src/app/debugger.ts
index 95712fb2ac..6255a52205 100644
--- a/apps/debugger/src/app/debugger.ts
+++ b/apps/debugger/src/app/debugger.ts
@@ -1,7 +1,7 @@
 import { PluginClient } from "@remixproject/plugin";
 import { createClient } from "@remixproject/plugin-webview";
 import { IDebuggerApi, RawLocation, Sources, Asts, LineColumnLocation, 
-  onBreakpointClearedListener, onBreakpointAddedListener, onEditorContentChanged, TransactionReceipt } from '@remix-ui/debugger-ui'
+  onBreakpointClearedListener, onBreakpointAddedListener, onEditorContentChanged, onEnvChangedListener, TransactionReceipt } from '@remix-ui/debugger-ui'
 import { DebuggerApiMixin, CompilerAbstract} from './debugger-api'
 
 export class DebuggerClientApi extends DebuggerApiMixin(PluginClient) {  
@@ -18,6 +18,7 @@ export class DebuggerClientApi extends DebuggerApiMixin(PluginClient) {
   onBreakpointCleared: (listener: onBreakpointClearedListener) => void
   onBreakpointAdded: (listener: onBreakpointAddedListener) => void
   onEditorContentChanged: (listener: onEditorContentChanged) => void
+  onEnvChanged: (listener: onEnvChangedListener) => void
   discardHighlight: () => Promise<void>
   highlight: (lineColumnPos: LineColumnLocation, path: string) => Promise<void>
   fetchContractAndCompile: (address: string, currentReceipt: TransactionReceipt) => Promise<CompilerAbstract>
diff --git a/apps/remix-ide-e2e/src/tests/solidityUnittests.spec.ts b/apps/remix-ide-e2e/src/tests/solidityUnittests.spec.ts
index 2c3a43ebc4..a46781eaea 100644
--- a/apps/remix-ide-e2e/src/tests/solidityUnittests.spec.ts
+++ b/apps/remix-ide-e2e/src/tests/solidityUnittests.spec.ts
@@ -166,27 +166,41 @@ module.exports = {
       .verify.attributeEquals('*[data-id="uiPathInput"]', 'value', 'tests')
   },
 
-  'Solidity Unittests': function (browser: NightwatchBrowser) {
-    runTests(browser)
-  }
-}
+  'Solidity Unit tests Basic': function (browser: NightwatchBrowser) {
+    browser
+      .waitForElementPresent('*[data-id="verticalIconsKindfilePanel"]')
+      .clickLaunchIcon('filePanel')
+      .click('*[data-id="treeViewLitreeViewItemcontracts"]')
+      .openFile('contracts/3_Ballot.sol')
+      .clickLaunchIcon('solidityUnitTesting')
+      .pause(2000)
+      .verify.attributeEquals('*[data-id="uiPathInput"]', 'value', 'tests')
+      .scrollAndClick('#runTestsTabRunAction')
+      .waitForElementVisible('*[data-id="testTabSolidityUnitTestsOutputheader"]', 120000)
+      .waitForElementPresent('#solidityUnittestsOutput div[class^="testPass"]', 60000)
+      .waitForElementContainsText('#solidityUnittestsOutput', '/tests/4_Ballot_test.sol', 60000)
+      .waitForElementContainsText('#solidityUnittestsOutput', '✓ Check winning proposal', 60000)
+      .waitForElementContainsText('#solidityUnittestsOutput', '✓ Check winnin proposal with return value', 60000)
+  },
 
-function runTests (browser: NightwatchBrowser) {
-  browser
-    .waitForElementPresent('*[data-id="verticalIconsKindfilePanel"]')
-    .clickLaunchIcon('filePanel')
-    .click('*[data-id="treeViewLitreeViewItemcontracts"]')
-    .openFile('contracts/3_Ballot.sol')
-    .clickLaunchIcon('solidityUnitTesting')
-    .pause(2000)
-    .verify.attributeEquals('*[data-id="uiPathInput"]', 'value', 'tests')
-    .scrollAndClick('#runTestsTabRunAction')
-    .waitForElementVisible('*[data-id="testTabSolidityUnitTestsOutputheader"]', 120000)
-    .waitForElementPresent('#solidityUnittestsOutput div[class^="testPass"]', 60000)
-    .waitForElementContainsText('#solidityUnittestsOutput', '/tests/4_Ballot_test.sol', 60000)
-    .waitForElementContainsText('#solidityUnittestsOutput', '✓ Check winning proposal', 60000)
-    .waitForElementContainsText('#solidityUnittestsOutput', '✓ Check winnin proposal with return value', 60000)
-    .end()
+  'Solidity Unit tests Basic Basic with local compiler': function (browser: NightwatchBrowser) {
+    browser
+      .clickLaunchIcon('solidity')
+      .setSolidityCompilerVersion('builtin')
+      .openFile('contracts/3_Ballot.sol')
+      .clickLaunchIcon('pluginManager')
+      .scrollAndClick('[data-id="pluginManagerComponentDeactivateButtonsolidityUnitTesting"]')
+      .pause(2000)
+      .scrollAndClick('[data-id="pluginManagerComponentActivateButtonsolidityUnitTesting"]')
+      .clickLaunchIcon('solidityUnitTesting')
+      .scrollAndClick('#runTestsTabRunAction')
+      .waitForElementVisible('*[data-id="testTabSolidityUnitTestsOutputheader"]', 120000)
+      .waitForElementPresent('#solidityUnittestsOutput div[class^="testPass"]', 60000)
+      .waitForElementContainsText('#solidityUnittestsOutput', '/tests/4_Ballot_test.sol', 60000)
+      .waitForElementContainsText('#solidityUnittestsOutput', '✓ Check winning proposal', 60000)
+      .waitForElementContainsText('#solidityUnittestsOutput', '✓ Check winnin proposal with return value', 60000)
+      .end()
+  }
 }
 
 const sources = [
diff --git a/apps/remix-ide/src/app/tabs/test-tab.js b/apps/remix-ide/src/app/tabs/test-tab.js
index 6750efde55..030745e5d1 100644
--- a/apps/remix-ide/src/app/tabs/test-tab.js
+++ b/apps/remix-ide/src/app/tabs/test-tab.js
@@ -278,6 +278,8 @@ module.exports = class TestTab extends ViewPlugin {
           </div>
         `)
       }
+    } else if (result.type === 'logOnly') {
+      if (result.hhLogs && result.hhLogs.length) this.printHHLogs(result.hhLogs, result.value)
     }
   }
 
diff --git a/apps/remix-ide/src/blockchain/providers/injected.js b/apps/remix-ide/src/blockchain/providers/injected.js
index 074fcfbf2a..f1272dc058 100644
--- a/apps/remix-ide/src/blockchain/providers/injected.js
+++ b/apps/remix-ide/src/blockchain/providers/injected.js
@@ -12,7 +12,7 @@ class InjectedProvider {
 
   newAccount (passwordPromptCb, cb) {
     passwordPromptCb((passphrase) => {
-      this.executionContext.web3().personal.newAccount(passphrase, cb)
+      this.executionContext.web3().eth.personal.newAccount(passphrase, cb)
     })
   }
 
diff --git a/apps/remix-ide/src/blockchain/providers/node.js b/apps/remix-ide/src/blockchain/providers/node.js
index abe407c3f3..b62158ec69 100644
--- a/apps/remix-ide/src/blockchain/providers/node.js
+++ b/apps/remix-ide/src/blockchain/providers/node.js
@@ -10,7 +10,7 @@ class NodeProvider {
 
   getAccounts (cb) {
     if (this.config.get('settings/personal-mode')) {
-      return this.executionContext.web3().personal.getListAccounts(cb)
+      return this.executionContext.web3().eth.personal.getAccounts(cb)
     }
     return this.executionContext.web3().eth.getAccounts(cb)
   }
@@ -20,7 +20,7 @@ class NodeProvider {
       return cb('Not running in personal mode')
     }
     passwordPromptCb((passphrase) => {
-      this.executionContext.web3().personal.newAccount(passphrase, cb)
+      this.executionContext.web3().eth.personal.newAccount(passphrase, cb)
     })
   }
 
diff --git a/libs/remix-analyzer/package.json b/libs/remix-analyzer/package.json
index 07cc68cce7..5c8c540cd6 100644
--- a/libs/remix-analyzer/package.json
+++ b/libs/remix-analyzer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-analyzer",
-  "version": "0.5.14",
+  "version": "0.5.15",
   "description": "Tool to perform static analysis on Solidity smart contracts",
   "main": "index.js",
   "types": ".index.d.ts",
@@ -23,7 +23,7 @@
     "@ethereumjs/tx": "^3.3.0",
     "@ethereumjs/vm": "^5.5.0",
     "@remix-project/remix-astwalker": "^0.0.26",
-    "@remix-project/remix-lib": "^0.5.5",
+    "@remix-project/remix-lib": "^0.5.6",
     "async": "^2.6.2",
     "ethereumjs-util": "^7.0.10",
     "ethers": "^5.4.2",
@@ -51,5 +51,5 @@
     "typescript": "^3.7.5"
   },
   "typings": "index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-astwalker/package.json b/libs/remix-astwalker/package.json
index c8e1b4d1fb..9cad741559 100644
--- a/libs/remix-astwalker/package.json
+++ b/libs/remix-astwalker/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-astwalker",
-  "version": "0.0.35",
+  "version": "0.0.36",
   "description": "Tool to walk through Solidity AST",
   "main": "index.js",
   "scripts": {
@@ -37,7 +37,7 @@
     "@ethereumjs/block": "^3.4.0",
     "@ethereumjs/tx": "^3.3.0",
     "@ethereumjs/vm": "^5.5.0",
-    "@remix-project/remix-lib": "^0.5.5",
+    "@remix-project/remix-lib": "^0.5.6",
     "@types/tape": "^4.2.33",
     "async": "^2.6.2",
     "ethereumjs-util": "^7.0.10",
@@ -53,5 +53,5 @@
     "tap-spec": "^5.0.0"
   },
   "typings": "index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-debug/package.json b/libs/remix-debug/package.json
index 105a423a65..33b2d1cd6c 100644
--- a/libs/remix-debug/package.json
+++ b/libs/remix-debug/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-debug",
-  "version": "0.5.5",
+  "version": "0.5.6",
   "description": "Tool to debug Ethereum transactions",
   "contributors": [
     {
@@ -23,7 +23,7 @@
     "@ethereumjs/tx": "^3.3.0",
     "@ethereumjs/vm": "^5.5.0",
     "@remix-project/remix-astwalker": "^0.0.26",
-    "@remix-project/remix-lib": "^0.5.5",
+    "@remix-project/remix-lib": "^0.5.6",
     "async": "^2.6.2",
     "commander": "^2.19.0",
     "deep-equal": "^1.0.1",
@@ -61,5 +61,5 @@
   },
   "homepage": "https://github.com/ethereum/remix-project/tree/master/libs/remix-debug#readme",
   "typings": "src/index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-lib/package.json b/libs/remix-lib/package.json
index fd868cb7d0..fa3c16e30c 100644
--- a/libs/remix-lib/package.json
+++ b/libs/remix-lib/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-lib",
-  "version": "0.5.5",
+  "version": "0.5.6",
   "description": "Library to various Remix tools",
   "contributors": [
     {
@@ -53,5 +53,5 @@
   },
   "homepage": "https://github.com/ethereum/remix-project/tree/master/libs/remix-lib#readme",
   "typings": "src/index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-simulator/package.json b/libs/remix-simulator/package.json
index 98c1b3d695..1f899f5751 100644
--- a/libs/remix-simulator/package.json
+++ b/libs/remix-simulator/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-simulator",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "description": "Ethereum IDE and tools for the web",
   "contributors": [
     {
@@ -18,7 +18,7 @@
     "@ethereumjs/common": "^2.2.0",
     "@ethereumjs/tx": "^3.3.0",
     "@ethereumjs/vm": "^5.5.0",
-    "@remix-project/remix-lib": "^0.5.5",
+    "@remix-project/remix-lib": "^0.5.6",
     "ansi-gray": "^0.1.1",
     "async": "^3.1.0",
     "body-parser": "^1.18.2",
@@ -66,5 +66,5 @@
   },
   "homepage": "https://github.com/ethereum/remix-project/tree/master/libs/remix-simulator#readme",
   "typings": "src/index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-solidity/package.json b/libs/remix-solidity/package.json
index 6e6f38bdf3..c7b002f939 100644
--- a/libs/remix-solidity/package.json
+++ b/libs/remix-solidity/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-solidity",
-  "version": "0.4.5",
+  "version": "0.4.6",
   "description": "Tool to load and run Solidity compiler",
   "main": "index.js",
   "types": "./index.d.ts",
@@ -18,7 +18,7 @@
     "@ethereumjs/block": "^3.4.0",
     "@ethereumjs/tx": "^3.3.0",
     "@ethereumjs/vm": "^5.5.0",
-    "@remix-project/remix-lib": "^0.5.5",
+    "@remix-project/remix-lib": "^0.5.6",
     "async": "^2.6.2",
     "eslint-scope": "^5.0.0",
     "ethereumjs-util": "^7.0.10",
@@ -59,5 +59,5 @@
   },
   "homepage": "https://github.com/ethereum/remix-project/tree/master/libs/remix-solidity#readme",
   "typings": "index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-solidity/src/compiler/compiler-utils.ts b/libs/remix-solidity/src/compiler/compiler-utils.ts
index da3bc487b3..7e19ae7d8a 100644
--- a/libs/remix-solidity/src/compiler/compiler-utils.ts
+++ b/libs/remix-solidity/src/compiler/compiler-utils.ts
@@ -12,9 +12,21 @@ export const pathToURL = {}
  * @param version is the version of compiler with or without 'soljson-v' prefix and .js postfix
  */
 export function urlFromVersion (version) {
-  if (!version.startsWith('soljson-v')) version = 'soljson-v' + version
-  if (!version.endsWith('.js')) version = version + '.js'
-  return `${pathToURL[version]}/${version}`
+  let url
+  if (version === 'builtin') {
+    let location: string | Location = window.document.location
+    let path = location.pathname
+    if (!path.startsWith('/')) path = '/' + path
+    location = `${location.protocol}//${location.host}${path}assets/js`
+    if (location.endsWith('index.html')) location = location.substring(0, location.length - 10)
+    if (!location.endsWith('/')) location += '/'
+    url = `${location}soljson.js`
+  } else {
+    if (!version.startsWith('soljson-v')) version = 'soljson-v' + version
+    if (!version.endsWith('.js')) version = version + '.js'
+    url = `${pathToURL[version]}/${version}`
+  }
+  return url
 }
 
 /**
diff --git a/libs/remix-tests/package.json b/libs/remix-tests/package.json
index bf1ea69207..86c199618c 100644
--- a/libs/remix-tests/package.json
+++ b/libs/remix-tests/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-tests",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "description": "Tool to test Solidity smart contracts",
   "main": "src/index.js",
   "types": "./src/index.d.ts",
@@ -39,9 +39,9 @@
     "@ethereumjs/common": "^2.2.0",
     "@ethereumjs/tx": "^3.3.0",
     "@ethereumjs/vm": "^5.5.0",
-    "@remix-project/remix-lib": "^0.5.5",
-    "@remix-project/remix-simulator": "^0.2.5",
-    "@remix-project/remix-solidity": "^0.4.5",
+    "@remix-project/remix-lib": "^0.5.6",
+    "@remix-project/remix-simulator": "^0.2.6",
+    "@remix-project/remix-solidity": "^0.4.6",
     "ansi-gray": "^0.1.1",
     "async": "^2.6.0",
     "axios": ">=0.21.1",
@@ -77,5 +77,5 @@
     "typescript": "^3.3.1"
   },
   "typings": "src/index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remix-tests/src/testRunner.ts b/libs/remix-tests/src/testRunner.ts
index 47b44d708b..ffc2cecde4 100644
--- a/libs/remix-tests/src/testRunner.ts
+++ b/libs/remix-tests/src/testRunner.ts
@@ -244,8 +244,15 @@ export function runTest (testName: string, testObject: any, contractDetails: Com
     const method = testObject.methods[func.name].apply(testObject.methods[func.name], [])
     const startTime = Date.now()
     if (func.constant) {
-      method.call(sendParams).then((result) => {
+      sendParams = {}
+      const tagTimestamp = 'remix_tests_tag' + Date.now()
+      sendParams.timestamp = tagTimestamp
+      method.call(sendParams).then(async (result) => {
         const time = (Date.now() - startTime) / 1000.0
+        let tagTxHash
+        let hhLogs
+        if (web3.eth && web3.eth.getHashFromTagBySimulator) tagTxHash = await web3.eth.getHashFromTagBySimulator(tagTimestamp)
+        if (web3.eth && web3.eth.getHHLogsForTx) hhLogs = await web3.eth.getHHLogsForTx(tagTxHash)
         if (result) {
           const resp: TestResultInterface = {
             type: 'testPass',
@@ -254,6 +261,7 @@ export function runTest (testName: string, testObject: any, contractDetails: Com
             time: time,
             context: testName
           }
+          if (hhLogs) resp.hhLogs = hhLogs
           testCallback(undefined, resp)
           passingNum += 1
           timePassed += time
@@ -266,6 +274,7 @@ export function runTest (testName: string, testObject: any, contractDetails: Com
             errMsg: 'function returned false',
             context: testName
           }
+          if (hhLogs) resp.hhLogs = hhLogs
           testCallback(undefined, resp)
           failureNum += 1
           timePassed += time
@@ -338,6 +347,17 @@ export function runTest (testName: string, testObject: any, contractDetails: Com
             testCallback(undefined, resp)
             passingNum += 1
             timePassed += time
+          } else if (hhLogs) {
+            const resp: TestResultInterface = {
+              type: 'logOnly',
+              value: changeCase.sentenceCase(func.name),
+              filename: testObject.filename,
+              time: time,
+              context: testName,
+              hhLogs
+            }
+            testCallback(undefined, resp)
+            timePassed += time
           }
 
           return next()
diff --git a/libs/remix-ui/debugger-ui/src/lib/debugger-ui.tsx b/libs/remix-ui/debugger-ui/src/lib/debugger-ui.tsx
index 0def604fdc..e79ad8910c 100644
--- a/libs/remix-ui/debugger-ui/src/lib/debugger-ui.tsx
+++ b/libs/remix-ui/debugger-ui/src/lib/debugger-ui.tsx
@@ -31,7 +31,8 @@ export const DebuggerUI = (props: DebuggerUIProps) => {
     },
     toastMessage: '',
     validationError: '',
-    txNumberIsEmpty: true
+    txNumberIsEmpty: true,
+    isLocalNodeUsed: false
   })
 
   useEffect(() => {
@@ -62,6 +63,17 @@ export const DebuggerUI = (props: DebuggerUIProps) => {
     }
 
     setEditor()
+
+    const providerChanged = () => {
+      debuggerModule.onEnvChanged((provider) => {
+        setState(prevState => {
+          const isLocalNodeUsed = provider !== 'vm' && provider !== 'injected'
+          return { ...prevState, isLocalNodeUsed: isLocalNodeUsed }
+        })
+      })
+    }
+
+    providerChanged()
   }, [state.debugger])
 
   const listenToEvents = (debuggerInstance, currentReceipt) => {
@@ -289,7 +301,7 @@ export const DebuggerUI = (props: DebuggerUIProps) => {
             }} type="checkbox" title="Debug with generated sources" />
             <label data-id="debugGeneratedSourcesLabel" className="form-check-label custom-control-label" htmlFor="debugGeneratedSourcesInput">Use generated sources (from Solidity v0.7.2)</label>
           </div>
-          <div className="mt-2 mb-2 debuggerConfig custom-control custom-checkbox">
+          { state.isLocalNodeUsed && <div className="mt-2 mb-2 debuggerConfig custom-control custom-checkbox">
             <input className="custom-control-input" id="debugWithLocalNodeInput" onChange={({ target: { checked } }) => {
               setState(prevState => {
                 return { ...prevState, opt: { ...prevState.opt, debugWithLocalNode: checked } }
@@ -297,6 +309,7 @@ export const DebuggerUI = (props: DebuggerUIProps) => {
             }} type="checkbox" title="Force the debugger to use the current local node" />
             <label data-id="debugLocaNodeLabel" className="form-check-label custom-control-label" htmlFor="debugWithLocalNodeInput">Force using local node</label>
           </div>
+          }
           { state.validationError && <span className="w-100 py-1 text-danger validationError">{state.validationError}</span> }
         </div>
         <TxBrowser requestDebug={ requestDebug } unloadRequested={ unloadRequested } updateTxNumberFlag={ updateTxNumberFlag } transactionNumber={ state.txNumber } debugging={ state.debugging } />
diff --git a/libs/remix-ui/debugger-ui/src/lib/idebugger-api.ts b/libs/remix-ui/debugger-ui/src/lib/idebugger-api.ts
index 4e31ce7360..2e57aff5a6 100644
--- a/libs/remix-ui/debugger-ui/src/lib/idebugger-api.ts
+++ b/libs/remix-ui/debugger-ui/src/lib/idebugger-api.ts
@@ -46,6 +46,7 @@ export type onBreakpointClearedListener = (params: string, row: number) => void
 export type onBreakpointAddedListener = (params: string, row: number) => void
 export type onEditorContentChanged = () => void
 export type onDebugRequested = (hash: string) => void
+export type onEnvChangedListener = (provider: string) => void
 
 export interface IDebuggerApi {
     offsetToLineColumnConverter: { offsetToLineColumn: (sourceLocation: RawLocation, file: number, contents: Sources, asts: Asts) => Promise<LineColumnLocation> }
@@ -57,6 +58,7 @@ export interface IDebuggerApi {
     onBreakpointCleared: (listener: onBreakpointClearedListener) => void
     onBreakpointAdded: (listener: onBreakpointAddedListener) => void
     onEditorContentChanged: (listener: onEditorContentChanged) => void
+    onEnvChanged: (listener: onEnvChangedListener) => void
     discardHighlight: () => Promise<void>
     highlight: (lineColumnPos: LineColumnLocation, path: string) => Promise<void>
     fetchContractAndCompile: (address: string, currentReceipt: TransactionReceipt) => Promise<CompilationOutput>
diff --git a/libs/remix-ui/debugger-ui/src/lib/vm-debugger/global-variables.tsx b/libs/remix-ui/debugger-ui/src/lib/vm-debugger/global-variables.tsx
index db26cf980b..98713182cd 100644
--- a/libs/remix-ui/debugger-ui/src/lib/vm-debugger/global-variables.tsx
+++ b/libs/remix-ui/debugger-ui/src/lib/vm-debugger/global-variables.tsx
@@ -5,7 +5,6 @@ import { BN } from 'ethereumjs-util'
 export const GlobalVariables = ({ block, receipt, tx }) => {
   // see https://docs.soliditylang.org/en/latest/units-and-global-variables.html#block-and-transaction-properties
   const globals = {
-    'block.basefee': (new BN(block.baseFeePerGas.replace('0x', ''), 'hex')).toString(10) + ` Wei (${block.baseFeePerGas})`,
     'block.chainid': tx.chainId,
     'block.coinbase': block.miner,
     'block.difficulty': block.difficulty,
@@ -17,6 +16,10 @@ export const GlobalVariables = ({ block, receipt, tx }) => {
     'msg.value': tx.value + ' Wei',
     'tx.origin': tx.from
   }
+  if (block.baseFeePerGas) {
+    globals['block.basefee'] = (new BN(block.baseFeePerGas.replace('0x', ''), 'hex')).toString(10) + ` Wei (${block.baseFeePerGas})`
+  }
+
   return (
     <div id='globalvariable' data-id='globalvariable'>
       <DropdownPanel hexHighlight={false} bodyStyle={{ fontFamily: 'monospace' }} dropdownName='Global Variables' calldata={globals || {}} />
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 9469121adf..80b1004ab6 100644
--- a/libs/remix-ui/solidity-compiler/src/lib/compiler-container.tsx
+++ b/libs/remix-ui/solidity-compiler/src/lib/compiler-container.tsx
@@ -333,19 +333,15 @@ export const CompilerContainer = (props: CompilerContainerProps) => {
       updateCurrentVersion(selectedVersion)
       url = customUrl
       api.setParameters({ version: selectedVersion })
-    } else if (selectedVersion === 'builtin') {
-      let location: string | Location = window.document.location
-      let path = location.pathname
-      if (!path.startsWith('/')) path = '/' + path
-      location = `${location.protocol}//${location.host}${path}assets/js`
-      if (location.endsWith('index.html')) location = location.substring(0, location.length - 10)
-      if (!location.endsWith('/')) location += '/'
-      url = location + 'soljson.js'
     } else {
-      if (selectedVersion.indexOf('soljson') !== 0 || helper.checkSpecialChars(selectedVersion)) {
-        return console.log('loading ' + selectedVersion + ' not allowed')
+      if (helper.checkSpecialChars(selectedVersion)) {
+        return console.log('loading ' + selectedVersion + ' not allowed, special chars not allowed.')
+      }
+      if (selectedVersion === 'builtin' || selectedVersion.indexOf('soljson') === 0) {
+        url = urlFromVersion(selectedVersion)
+      } else {
+        return console.log('loading ' + selectedVersion + ' not allowed, version should start with "soljson"')
       }
-      url = `${urlFromVersion(selectedVersion)}`
     }
 
     // Workers cannot load js on "file:"-URLs and we get a
diff --git a/libs/remix-url-resolver/package.json b/libs/remix-url-resolver/package.json
index a9b6770890..00bd82df23 100644
--- a/libs/remix-url-resolver/package.json
+++ b/libs/remix-url-resolver/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remix-url-resolver",
-  "version": "0.0.26",
+  "version": "0.0.27",
   "description": "Solidity import url resolver engine",
   "main": "index.js",
   "types": "./index.d.ts",
@@ -42,5 +42,5 @@
     "typescript": "^3.1.6"
   },
   "typings": "index.d.ts",
-  "gitHead": "df7abe1c219e361a947031d620f4ae6e3786a4d7"
+  "gitHead": "39700b7c076d53d0f857f341774a8448ea5c8da9"
 }
\ No newline at end of file
diff --git a/libs/remixd/package.json b/libs/remixd/package.json
index 6f9123c651..3cb0baddd7 100644
--- a/libs/remixd/package.json
+++ b/libs/remixd/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@remix-project/remixd",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "remix server: allow accessing file system from remix.ethereum.org and start a dev environment (see help section)",
   "main": "index.js",
   "types": "./index.d.ts",
diff --git a/package-lock.json b/package-lock.json
index d3372b8379..dc010b4ac4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "remix-project",
-  "version": "0.17.0-dev",
+  "version": "0.18.0-dev",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -3553,6 +3553,12 @@
         "@fortawesome/fontawesome-common-types": "^0.2.34"
       }
     },
+    "@gar/promisify": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/@gar/promisify/-/promisify-1.1.2.tgz",
+      "integrity": "sha512-82cpyJyKRoQoRi+14ibCeGPu0CwypgtBAdBhq1WfvagpCZNKqwXbKwXllYSMG91DhmG4jt9gN8eP6lGOtozuaw==",
+      "dev": true
+    },
     "@istanbuljs/load-nyc-config": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/@istanbuljs/load-nyc-config/-/load-nyc-config-1.1.0.tgz",
@@ -5886,6 +5892,42 @@
       "integrity": "sha512-oN3y7FAROHhrAt7Rr7PnTSwrHrZVRTS2ZbyxeQwSSYD0ifwM3YNgQqbaRmjcWoPyq77MjchusjJDspbzMmip1Q==",
       "dev": true
     },
+    "@npmcli/fs": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@npmcli/fs/-/fs-1.0.0.tgz",
+      "integrity": "sha512-8ltnOpRR/oJbOp8vaGUnipOi3bqkcW+sLHFlyXIr08OGHmVJLB1Hn7QtGXbYcpVtH1gAYZTlmDXtE4YV0+AMMQ==",
+      "dev": true,
+      "requires": {
+        "@gar/promisify": "^1.0.1",
+        "semver": "^7.3.5"
+      },
+      "dependencies": {
+        "lru-cache": {
+          "version": "6.0.0",
+          "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
+          "integrity": "sha512-Jo6dJ04CmSjuznwJSS3pUeWmd/H0ffTlkXXgwZi+eq1UCmqQwCh+eLsYOYCwY991i2Fah4h1BEMCx4qThGbsiA==",
+          "dev": true,
+          "requires": {
+            "yallist": "^4.0.0"
+          }
+        },
+        "semver": {
+          "version": "7.3.5",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-7.3.5.tgz",
+          "integrity": "sha512-PoeGJYh8HK4BTO/a9Tf6ZG3veo/A7ZVsYrSA6J8ny9nb3B1VrpkuN+z9OE5wfE5p6H4LchYZsegiQgbJD94ZFQ==",
+          "dev": true,
+          "requires": {
+            "lru-cache": "^6.0.0"
+          }
+        },
+        "yallist": {
+          "version": "4.0.0",
+          "resolved": "https://registry.npmjs.org/yallist/-/yallist-4.0.0.tgz",
+          "integrity": "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==",
+          "dev": true
+        }
+      }
+    },
     "@npmcli/git": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/@npmcli/git/-/git-2.0.3.tgz",
@@ -11344,17 +11386,6 @@
             }
           }
         },
-        "fsevents": {
-          "version": "1.2.13",
-          "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-1.2.13.tgz",
-          "integrity": "sha512-oWb1Z6mkHIskLzEJ/XWX0srkpkTQ7vaopMQkyaEIoq0fmtFVxOthb8cCxeT+p3ynTdkk/RZwbgG4brR5BeWECw==",
-          "dev": true,
-          "optional": true,
-          "requires": {
-            "bindings": "^1.5.0",
-            "nan": "^2.12.1"
-          }
-        },
         "glob-parent": {
           "version": "2.0.0",
           "resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-2.0.0.tgz",
@@ -12175,16 +12206,6 @@
             "to-regex-range": "^2.1.0"
           }
         },
-        "fsevents": {
-          "version": "1.2.13",
-          "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-1.2.13.tgz",
-          "integrity": "sha512-oWb1Z6mkHIskLzEJ/XWX0srkpkTQ7vaopMQkyaEIoq0fmtFVxOthb8cCxeT+p3ynTdkk/RZwbgG4brR5BeWECw==",
-          "optional": true,
-          "requires": {
-            "bindings": "^1.5.0",
-            "nan": "^2.12.1"
-          }
-        },
         "glob-parent": {
           "version": "3.1.0",
           "resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-3.1.0.tgz",
@@ -17502,6 +17523,16 @@
       "resolved": "https://registry.npmjs.org/fs.realpath/-/fs.realpath-1.0.0.tgz",
       "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8="
     },
+    "fsevents": {
+      "version": "1.2.13",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-1.2.13.tgz",
+      "integrity": "sha512-oWb1Z6mkHIskLzEJ/XWX0srkpkTQ7vaopMQkyaEIoq0fmtFVxOthb8cCxeT+p3ynTdkk/RZwbgG4brR5BeWECw==",
+      "optional": true,
+      "requires": {
+        "bindings": "^1.5.0",
+        "nan": "^2.12.1"
+      }
+    },
     "fstream": {
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/fstream/-/fstream-1.0.11.tgz",
@@ -30236,17 +30267,6 @@
             }
           }
         },
-        "fsevents": {
-          "version": "1.2.13",
-          "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-1.2.13.tgz",
-          "integrity": "sha512-oWb1Z6mkHIskLzEJ/XWX0srkpkTQ7vaopMQkyaEIoq0fmtFVxOthb8cCxeT+p3ynTdkk/RZwbgG4brR5BeWECw==",
-          "dev": true,
-          "optional": true,
-          "requires": {
-            "bindings": "^1.5.0",
-            "nan": "^2.12.1"
-          }
-        },
         "glob-parent": {
           "version": "2.0.0",
           "resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-2.0.0.tgz",
@@ -37033,11 +37053,12 @@
           "dev": true
         },
         "cacache": {
-          "version": "15.2.0",
-          "resolved": "https://registry.npmjs.org/cacache/-/cacache-15.2.0.tgz",
-          "integrity": "sha512-uKoJSHmnrqXgthDFx/IU6ED/5xd+NNGe+Bb+kLZy7Ku4P+BaiWEUflAKPZ7eAzsYGcsAGASJZsybXp+quEcHTw==",
+          "version": "15.3.0",
+          "resolved": "https://registry.npmjs.org/cacache/-/cacache-15.3.0.tgz",
+          "integrity": "sha512-VVdYzXEn+cnbXpFgWs5hTT7OScegHVmLhJIR8Ufqk3iFD6A6j5iSX1KuBTfNEv4tdJWE2PzA6IVFtcLC7fN9wQ==",
           "dev": true,
           "requires": {
+            "@npmcli/fs": "^1.0.0",
             "@npmcli/move-file": "^1.0.1",
             "chownr": "^2.0.0",
             "fs-minipass": "^2.0.0",
@@ -37064,9 +37085,9 @@
           "dev": true
         },
         "find-cache-dir": {
-          "version": "3.3.1",
-          "resolved": "https://registry.npmjs.org/find-cache-dir/-/find-cache-dir-3.3.1.tgz",
-          "integrity": "sha512-t2GDMt3oGC/v+BMwzmllWDuJF/xcDtE5j/fCGbqDD7OLuJkj0cfh1YSA5VKPvwMeLFLNDBkwOKZ2X85jGLVftQ==",
+          "version": "3.3.2",
+          "resolved": "https://registry.npmjs.org/find-cache-dir/-/find-cache-dir-3.3.2.tgz",
+          "integrity": "sha512-wXZV5emFEjrridIgED11OoUKLxiYjAcqot/NJdAkOhlJ+vGzwhOAfcG5OX1jP+S0PcjEn8bdMJv+g2jwQ3Onig==",
           "dev": true,
           "requires": {
             "commondir": "^1.0.1",
@@ -37257,9 +37278,9 @@
           }
         },
         "tar": {
-          "version": "6.1.10",
-          "resolved": "https://registry.npmjs.org/tar/-/tar-6.1.10.tgz",
-          "integrity": "sha512-kvvfiVvjGMxeUNB6MyYv5z7vhfFRwbwCXJAeL0/lnbrttBVqcMOnpHUf0X42LrPMR8mMpgapkJMchFH4FSHzNA==",
+          "version": "6.1.11",
+          "resolved": "https://registry.npmjs.org/tar/-/tar-6.1.11.tgz",
+          "integrity": "sha512-an/KZQzQUkZCkuoAA64hM92X0Urb6VpRhAFllDzz44U2mcD5scmT3zBc4VgVpkugF580+DQn8eAFSyoQt0tznA==",
           "dev": true,
           "requires": {
             "chownr": "^2.0.0",
@@ -37271,9 +37292,9 @@
           }
         },
         "terser": {
-          "version": "5.7.1",
-          "resolved": "https://registry.npmjs.org/terser/-/terser-5.7.1.tgz",
-          "integrity": "sha512-b3e+d5JbHAe/JSjwsC3Zn55wsBIM7AsHLjKxT31kGCldgbpFePaFo+PiddtO6uwRZWRw7sPXmAN8dTW61xmnSg==",
+          "version": "5.7.2",
+          "resolved": "https://registry.npmjs.org/terser/-/terser-5.7.2.tgz",
+          "integrity": "sha512-0Omye+RD4X7X69O0eql3lC4Heh/5iLj3ggxR/B5ketZLOtLiOqukUgjw3q4PDnNQbsrkKr3UMypqStQG3XKRvw==",
           "dev": true,
           "requires": {
             "commander": "^2.20.0",
diff --git a/package.json b/package.json
index 0175da3400..2bcbcd0b49 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "remix-project",
-  "version": "0.17.0-dev",
+  "version": "0.18.0-dev",
   "license": "MIT",
   "description": "Ethereum Remix Monorepo",
   "keywords": [