System.BadImageFormatException starting omnisharp server (osx-arm64)

Issue Description

Steps to Reproduce

1. Install prerelease 1.24.0 from VSIX to VS Code.
2. Observe output. Extension installs but Omnisharp server fails to start. Output:

Starting OmniSharp server at 1/15/2022, 4:01:18 PM
    Target: /Users/eck/Code/my-project

OmniSharp server started with .NET 6.0.100
.
    Path: /Users/eck/.vscode/extensions/ms-dotnettools.csharp-1.24.0/.omnisharp/1.38.1-beta.15-net6.0/OmniSharp.dll
    PID: 64647

Unhandled exception. System.BadImageFormatException: An attempt was made to load a program with an incorrect format.
 (0x8007000B)
[ERROR] Error: OmniSharp server load timed out. Use the 'omnisharp.projectLoadTimeout' setting to override the default delay (one minute).

Expected Behavior

Omnisharp server starts.

Actual Behavior

Omnisharp server does not start.

Logs

OmniSharp log

Post the output from Output-->OmniSharp log here

C# log

Post the output from Output-->C# here

Environment information

VSCode version: 1.63.2 C# Extension: 1.24.0

Mono Information

OmniSharp using built-in mono

Dotnet Information

.NET SDK (reflecting any global.json): Version: 6.0.100 Commit: 9e8b04bbff

Runtime Environment: OS Name: Mac OS X OS Version: 12.0 OS Platform: Darwin RID: osx-arm64 Base Path: /usr/local/share/dotnet/sdk/6.0.100/

Host (useful for support): Version: 6.0.0 Commit: 4822e3c3aa

.NET SDKs installed: 6.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed: Microsoft.AspNetCore.App 6.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 6.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

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

Visual Studio Code Extensions

Extension	Author	Version
csharp	ms-dotnettools	1.24.0
docomment	k–kato	0.1.30
githistory	donjayamanne	0.6.19
markdown-image-size	bierner	0.0.4
remote-containers	ms-vscode-remote	0.209.6
remote-ssh	ms-vscode-remote	0.70.0
remote-ssh-edit	ms-vscode-remote	0.70.0
sort-js-object-keys	zengxingxin	1.0.6
terraform	hashicorp	2.18.0
vscode-docker	ms-azuretools	1.18.0
vscode-kubernetes-tools	ms-kubernetes-tools	1.3.6
vscode-markdownlint	DavidAnson	0.45.0
vscode-sort	henriiik	0.2.5
vscode-yaml	redhat	1.3.0

[SaIG]

Had the same issue … and when installing the C# extension of vsCode it always downloaded the x64 version despite me having installed the arm64 dotnet version and deleted the x64 version.

Check if you have the old intel vscode version installed It said Intel here for me first so thats why he downloaded the x64 omisharp tools after updating to the “apple branch” of vscode it said apple there and it downloaded the correct arm64 version of it.

hope this helps!

[DrBlackBird]

I have the same error here. Without useModernNet Omnisharp loads but with the option enabled I receive the above error.