The Language Service Could not be started

[spidey323]

The extension wont even load so I can't get the PSVersion.
Everything was working fine until the update of the powershell extension.

Issue Description

The Language Service Could not be started
3/6/2020 8:24:21 AM [NORMAL] - Visual Studio Code v1.42.1 64-bit
3/6/2020 8:24:21 AM [NORMAL] - PowerShell Extension v2020.3.0
3/6/2020 8:24:21 AM [NORMAL] - Operating System: Windows 64-bit
3/6/2020 8:24:21 AM [NORMAL] - Language server starting --
3/6/2020 8:24:21 AM [NORMAL] -     PowerShell executable: C:\WINDOWS\System32\WindowsPowerShell\v1.0\powershell.exe
3/6/2020 8:24:21 AM [NORMAL] -     PowerShell args: -NoProfile -NonInteractive -ExecutionPolicy Bypass -Command Import-Module 'c:\Users\xxxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\modules\PowerShellEditorServices\PowerShellEditorServices.psd1'; Start-EditorServices -HostName 'Visual Studio Code Host' -HostProfileId 'Microsoft.VSCode' -HostVersion '2020.3.0' -AdditionalModules @('PowerShellEditorServices.VSCode') -BundledModulesPath 'c:\Users\xxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\modules' -EnableConsoleRepl -LogLevel 'Normal' -LogPath 'c:\Users\xxxxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\logs\1583504661-d29ecc6e-241c-4f6d-a6ef-96dc719a4e801583504610369\EditorServices.log' -SessionDetailsPath 'c:\Users\xxxxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\sessions\PSES-VSCode-16792-972902' -FeatureFlags @() 
3/6/2020 8:24:21 AM [NORMAL] -     PowerShell Editor Services args: Import-Module 'c:\Users\xxxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\modules\PowerShellEditorServices\PowerShellEditorServices.psd1'; Start-EditorServices -HostName 'Visual Studio Code Host' -HostProfileId 'Microsoft.VSCode' -HostVersion '2020.3.0' -AdditionalModules @('PowerShellEditorServices.VSCode') -BundledModulesPath 'c:\Users\xxxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\modules' -EnableConsoleRepl -LogLevel 'Normal' -LogPath 'c:\Users\michael.hagedorn\.vscode\extensions\ms-vscode.powershell-2020.3.0\logs\1583504661-d29ecc6e-241c-4f6d-a6ef-96dc719a4e801583504610369\EditorServices.log' -SessionDetailsPath 'c:\Users\xxxxx\.vscode\extensions\ms-vscode.powershell-2020.3.0\sessions\PSES-VSCode-16792-972902' -FeatureFlags @() 
3/6/2020 8:24:21 AM [NORMAL] - powershell.exe started.
3/6/2020 8:24:21 AM [NORMAL] - Waiting for session file
3/6/2020 8:26:21 AM [NORMAL] - Error occurred retrieving session file
3/6/2020 8:26:21 AM [NORMAL] - Language server startup failed.
3/6/2020 8:26:21 AM [ERROR] - The language service could not be started: 
3/6/2020 8:26:21 AM [ERROR] - Timed out waiting for session file to appear.

Name                           Value
----                           -----
PSVersion                      5.1.18362.628
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.18362.628
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

[rjmholt]

Everything was working fine until the update of the powershell extension.

This is at least a reasonable sign that it's some we might be able to fix. We've seen other issues like this where an OS update causes issues.

It looks like this is a session file issue but we don't log enough information to discern the problem. It might be available in VSCode's own logs (try the Developer: Show Logs option and pick Extension Host) or possibly in the developer tools console (available in the help menu -- looks like Chrome's dev tools console). Alternatively, if you install this build it should log the relevant information in the same log as the one you posted:

psvsix.zip

[spidey323]

I'm glad it looks fixable. I've tried uninstalling/re-installing several times. Looks like it happened with the update for March. (I even tried installing an older version. Appreciate your help.
Here's the log output from the above command:

[2020-03-06 13:56:12.488] [exthost] [info] extension host started
[2020-03-06 13:56:12.544] [exthost] [info] ExtensionService#_doActivateExtension vscode.debug-auto-launch {"startup":true,"extensionId":{"value":"vscode.debug-auto-launch","_lower":"vscode.debug-auto-launch"},"activationEvent":"*"}
[2020-03-06 13:56:12.545] [exthost] [info] ExtensionService#loadCommonJSModule file:///c:/Program Files/Microsoft VS Code/resources/app/extensions/debug-auto-launch/dist/extension
[2020-03-06 13:56:12.554] [exthost] [info] ExtensionService#_doActivateExtension vscode.emmet {"startup":true,"extensionId":{"value":"vscode.emmet","_lower":"vscode.emmet"},"activationEvent":"*"}
[2020-03-06 13:56:12.555] [exthost] [info] ExtensionService#loadCommonJSModule file:///c:/Program Files/Microsoft VS Code/resources/app/extensions/emmet/dist/extension
[2020-03-06 13:56:12.588] [exthost] [info] ExtensionService#_doActivateExtension vscode.git {"startup":true,"extensionId":{"value":"vscode.git","_lower":"vscode.git"},"activationEvent":"*"}
[2020-03-06 13:56:12.588] [exthost] [info] ExtensionService#loadCommonJSModule file:///c:/Program Files/Microsoft VS Code/resources/app/extensions/git/dist/main
[2020-03-06 13:56:12.634] [exthost] [info] ExtensionService#_doActivateExtension vscode.merge-conflict {"startup":true,"extensionId":{"value":"vscode.merge-conflict","_lower":"vscode.merge-conflict"},"activationEvent":"*"}
[2020-03-06 13:56:12.634] [exthost] [info] ExtensionService#loadCommonJSModule file:///c:/Program Files/Microsoft VS Code/resources/app/extensions/merge-conflict/dist/extension
[2020-03-06 13:56:12.641] [exthost] [info] ExtensionService#_doActivateExtension vscode.search-result {"startup":true,"extensionId":{"value":"vscode.search-result","_lower":"vscode.search-result"},"activationEvent":"*"}
[2020-03-06 13:56:12.641] [exthost] [info] ExtensionService#loadCommonJSModule file:///c:/Program Files/Microsoft VS Code/resources/app/extensions/search-result/dist/extension.js
[2020-03-06 13:56:12.645] [exthost] [info] ExtensionService#_doActivateExtension vscode.vscode-account {"startup":true,"extensionId":{"value":"vscode.vscode-account","_lower":"vscode.vscode-account"},"activationEvent":"*"}
[2020-03-06 13:56:12.645] [exthost] [info] ExtensionService#loadCommonJSModule file:///c:/Program Files/Microsoft VS Code/resources/app/extensions/vscode-account/dist/extension.js
[2020-03-06 13:56:12.651] [exthost] [info] eager extensions activated

[spidey323]

The application hangs as soon as I install the powershell ext so I have to keep it disabled. -FYI

[spidey323]

[rjmholt]

Here's the log output from the above command:

Hmmm, I don't see anything of use in there (unfortunately VSCode's own logs are quite opaque).

Could you try installing the (zipped) VSIX I linked above? Can do it like this:

expand-archive ./psvsix.zip ./psext.vsix
code --install-extension ./psext.vsix

You'll then need to disable the PowerShell extension (because the VSIX is a "PowerShell Preview" extension) and restart VSCode.

Hopefully that will log the reason for startup failure.

The hang you're seeing may well be #2377, which is a VSCode bug we're still waiting on a fix for.

[spidey323]

I dont see the link. The hang is more when the extension is trying to be loaded, that's what happens.
Please let me know how to get the VSIX. I need to get up and running asap. thanks

[spidey323]

I've already tried the Powershell preview ext and get the same behavior.

[TylerLeonhardt]

The link is in this comment: #2526 (comment)

[rjmholt]

Link

[happywino]

I started seeing the same issue today, possibly right after VSCode autoupdated. If I run the launch command from a regular command prompt here's the error I get;

Import-Module : The module manifest 'C:\Users\ad_jcphilli\.vscode\extensions\ms-vscode.powershell-2020.3.0\modules\Powe
rShellEditorServices\PowerShellEditorServices.psd1' could not be processed because it is not a valid Windows
PowerShell restricted language file. Remove the elements that are not permitted by the restricted language:
At C:\Users\ad_jcphilli\.vscode\extensions\ms-vscode.powershell-2020.3.0\modules\PowerShellEditorServices\PowerShellEdi
torServices.psd1:12 char:18
+ RootModule = if ($PSEdition -eq 'Core')
+                  ~~~~~~~~~~
A variable that cannot be referenced in restricted language mode or a Data section is being referenced. Variables that
can be referenced include the following: $PSCulture, $PSUICulture, $true, $false, and  $null.
At line:1 char:1
+ Import-Module 'c:\Users\ad_jcphilli\.vscode\extensions\ms-vscode.powershell-2020 ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ResourceUnavailable: (C:\Users\ad_jcp...orServices.psd1:String) [Import-Module], Missing
   MemberException
    + FullyQualifiedErrorId : Modules_InvalidManifest,Microsoft.PowerShell.Commands.ImportModuleCommand

Start-EditorServices : The term 'Start-EditorServices' is not recognized as the name of a cmdlet, function, script
file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct
and try again.
At line:1 char:151
+ ... ervices.psd1'; Start-EditorServices -HostName 'Visual Studio Code Host' -HostPro ...
+                    ~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Start-EditorServices:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

[spidey323]

@rjmholt Where do I place the psvsix.zip so code can unzip and install?

[happywino]

After a little more investigation I think the issue might be the use of $PSEdition in .vscode\extensions\ms-vscode.powershell-2020.3.0\modules\PowerShellEditorServices\PowerShellEditorServices.psd1

According to this source;

By default, only the following variables are permitted in RestrictedLanguage mode:

$PSCulture
$PSUICulture
$True
$False
$Null
Module manifests, which use RestrictedLanguage mode, permit the following additional variables as well:

$PSScriptRoot
$PSEdition (in PowerShell Core)
$EnabledExperimentalFeatures (in PowerShell Core)

I am not using PowerShell Core;

Name Value

---

PSVersion 4.0
WSManStackVersion 3.0
SerializationVersion 1.1.0.1
CLRVersion 4.0.30319.42000
BuildVersion 6.3.9600.19170
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0}
PSRemotingProtocolVersion 2.2

That said, when I change line 12 of the psd1 from

RootModule = if ($PSEdition -eq 'Core')
    {
        'bin/Core/Microsoft.PowerShell.EditorServices.Hosting.dll'
    }
    else
    {
        'bin/Desktop/Microsoft.PowerShell.EditorServices.Hosting.dll'
    }

to

RootModule = 'bin/Desktop/Microsoft.PowerShell.EditorServices.Hosting.dll'

I don't see the error but the terminal window displays the text below but never finishes loading.

 =====> PowerShell Integrated Console <=====