Ionide-vscode-fsharp: Failed to start language services. Please check if Microsoft Build Tools 2013 are installed

[lambdakris]

After a recent Ionide upgrade, I am getting the following message "Failed to start language services. Please check if Microsoft Build Tools 2013 are installed". I do not have Build Tools 2013, but I do have Build Tools 2015, and I thought that was the requirement as per the [Readme: Quick Install instructions] https://github.com/ionide/ionide-vscode-fsharp#quick-install-guide.

...I also wonder whether it is related to https://github.com/ionide/ionide-vscode-fsharp/issues/577

OS Version
Windows 10 1511
.NET Framework Version
4.6.1
.NET Core Version
2.0
Ionide Version
3.11.0

Here is the F# Language Service (server) output

Running: C:\Users\cax9124\.vscode\extensions\Ionide.ionide-fsharp-3.11.0/bin/fsautocomplete.exe --mode http --port 8919 --hostPID=9156
spawn C:\Users\cax9124\.vscode\extensions\Ionide.ionide-fsharp-3.11.0/bin/fsautocomplete.exe ENOENT

Here is the F# Language Service output

[11:22:18 ERROR] Failed to start language services. spawn C:\Users\cax9124\.vscode\extensions\Ionide.ionide-fsharp-3.11.0/bin/fsautocomplete.exe ENOENT

[lambdakris]

Launching vs code from command line inside project dir did not make a difference

[Krzysztof-Cieslak]

Please check if the file C:\Users\cax9124\.vscode\extensions\Ionide.ionide-fsharp-3.11.0/bin/fsautocomplete.exe for sure exists. If not try reinstalling extension (and make sure that antivirus or something like that is not messing with installation)

[lambdakris]

You were correct, fsautocomplete.exe was missing and the issue went away after re-installing the extension (did not have to adjust antivirus so it must have been a botched extension update). Appreciate your help.

[daz10000]

I just got a similar message suddenly. Was working earlier today and then restarted vscode on a project and it was gone. i suspect maybe antivirus took it out (avast loves to stomp on fsautocomplete.exe for some reason), but I didn't see it warn me. Would be nice if the project startup could diagnose this more specifically. The message MSbuild tools 2013 missing is a real red herring

[tymokvo]

This is happening for me after the latest VSCode update. fsautocomplete.exe exists in the extensions directory. Have tried reinstalling ionide too.

VSCode info:

Version: 1.31.0 (user setup)
Commit: 7c66f58312b48ed8ca4e387ebd9ffe9605332caa
Date: 2019-02-05T22:35:56.624Z
Electron: 3.1.2
Chrome: 66.0.3359.181
Node.js: 10.2.0
V8: 6.6.346.32
OS: Windows_NT x64 10.0.15063

Checking the Language Server log shows:

...
It was not possible to find any compatible framework version

The specified framework 'Microsoft.NETCore.App', version '2.1.0' was not found.

  - Check application dependencies and target a framework version installed at:

      \

  - Alternatively, install the framework version '2.1.0'.

Looks like the minimum version is now .NET Core 2.1.0? Not sure how this changed, but it was working before VSCode updated itself this morning for me.

[MangelMaxime]

This is probably related to this PR: https://github.com/fsharp/FsAutoComplete/pull/335

[tymokvo]

Installing .NET Core runtime > 2.1 (2.1.7) solved this for me. The MSBuild tools message is very confusing. Also annoying that Visual Studio Installer doesn't let you select a version of the runtime to install. 🙄

[Krzysztof-Cieslak]

Yes, I think I've silently upgraded the .Net Core requirement, sorry for that. And we definitely should have a better error message in this case. PRs welcomed? ;-)