Linux (Debian 10): System.IO.FileNotFoundException: Could not load file or assembly 'netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies.

Issue Description

When starting Visual Studio Code, the following message appears in the log: System.IO.FileNotFoundException: Could not load file or assembly 'netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies.

I’m using Debian 10, which I realize is not yet officially supported. If you feel like that might be the cause and don’t have the resources to investigate I understand.

Steps to Reproduce

Open a folder with a C# Solution in Visual Studio Code on an updated instance of Debian 10.

Expected Behavior

Omnisharp and thus Intellisense work.

Actual Behavior

Omnisharp server fails to start

Logs

OmniSharp log

Starting OmniSharp server at 9/6/2019, 8:49:43 PM Target: /home/lufix/src/emu/8080

OmniSharp server started with Mono 5.18.0. Path: /home/lufix/.vscode/extensions/ms-vscode.csharp-1.21.1/.omnisharp/1.34.2/omnisharp/OmniSharp.exe PID: 31312

System.IO.FileNotFoundException: Could not load file or assembly ‘netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51’ or one of its dependencies. File name: ‘netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51’ at OmniSharp.CommandLineApplication+<>c__DisplayClass11_0.<OnExecute>b__0 () [0x0000b] in <150636dc45ea41d3a8efdf330bb7b52f>:0 at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Execute (System.String[] args) [0x00039] in <344a1e8cd6594b17b1e01f8df6ae8827>:0 at OmniSharp.CommandLineApplication.Execute (System.Collections.Generic.IEnumerable1[T] args) [0x00042] in <150636dc45ea41d3a8efdf330bb7b52f>:0 at OmniSharp.Stdio.Driver.Program+<>c__DisplayClass0_0.<Main>b__0 () [0x00028] in <ef67332970734dbbb15e5d0e9b13d144>:0 at OmniSharp.HostHelpers.Start (System.Func1[TResult] action) [0x0001c] in <150636dc45ea41d3a8efdf330bb7b52f>:0 [ERROR] Error: OmniSharp server load timed out. Use the ‘omnisharp.projectLoadTimeout’ setting to override the default delay (one minute).

C# log

(blank)

Environment information

VSCode version: 1.38.0 C# Extension: 1.21.1

Mono Information

OmniSharp using global mono :5.18.0

Dotnet Information

.NET Core SDK (reflecting any global.json): Version: 2.2.401 Commit: 729b316c13

Runtime Environment: OS Name: debian OS Version: 10 OS Platform: Linux RID: debian.10-x64 Base Path: /usr/share/dotnet/sdk/2.2.401/

Host (useful for support): Version: 2.2.6 Commit: 7dac9b1b51

.NET Core SDKs installed: 2.2.401 [/usr/share/dotnet/sdk]

.NET Core runtimes installed: Microsoft.AspNetCore.All 2.2.6 [/usr/share/dotnet/shared/Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.2.6 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 2.2.6 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs: https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
cpptools	ms-vscode	0.25.1
csharp	ms-vscode	1.21.1
Go	ms-vscode	0.11.4
mssql	ms-mssql	1.6.0
vetur	octref	0.22.2
vscode-wasm	dtsvet	1.2.1

[dogguts]

I have(/had) exactly the same issue, with pretty much the same setup (safe for the extensions).

Fix (option 1)

Change settings to:

 "omnisharp.useGlobalMono": "never"

Forces omnisharp to use the mono version packaged with omnisharp. Worked for me.

Fix (option 2)

Install the latest (stable) mono version from www.mono-project.com and keep

 "omnisharp.useGlobalMono": "always"

or

"omnisharp.useGlobalMono": "auto" 

Also verified working (for me).

Possible(?) cause

According to github.com/OmniSharp/omnisharp-roslyn :

If Mono is globally installed on the system, OmniSharp will prefer it over the embedded version, however version >=5.18.0 is required.

However; package.json states:

• Automatically launch OmniSharp with “mono” if version 5.8.1 or greater is available on the PATH.",
• Always launch OmniSharp with “mono”. If version 5.8.1 or greater is not available on the PATH, an error will be printed.",
• Never launch OmniSharp on a globally-installed Mono."

Could be just an documentation inconsistency though. Or there’s something wrong with the debian 10 mono package(s), but I didn’t look any further into that.

Debian 10: (default) mono 5.18.0.240

Mono JIT compiler version 5.18.0.240 (Debian 5.18.0.240+dfsg-3 Wed Apr 17 16:37:36 UTC 2019) Copyright © 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com TLS: __thread SIGSEGV: altstack Notifications: epoll Architecture: amd64 Disabled: none Misc: softdebug Interpreter: yes LLVM: supported, not enabled. Suspend: preemptive GC: sgen (concurrent by default)

C# extension 1.21.3 / omnisharp 1.34.4-beta.6: mono 5.18.1.0

Mono JIT compiler version 5.18.1.0 (tarball Fri Mar 15 20:45:47 UTC 2019) Copyright © 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com TLS: __thread SIGSEGV: altstack Notifications: epoll Architecture: amd64 Disabled: none Misc: softdebug Interpreter: yes LLVM: yes(600) Suspend: preemptive GC: sgen (concurrent by default)

mono-project.com: mono 6.0.0.334

Mono JIT compiler version 6.0.0.334 (tarball Thu Sep 12 21:35:31 UTC 2019) Copyright © 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com TLS: __thread SIGSEGV: altstack Notifications: epoll Architecture: amd64 Disabled: none Misc: softdebug Interpreter: yes LLVM: yes(600) Suspend: hybrid GC: sgen (concurrent by default)

[GabrielFerrarini]

@dogguts thank you. This worked also for Pengwin.