Go to definition of project reference goes to decompiled output rather than the source

[UliPlabst]

Type: Bug

Issue Description

I have a large solution with multiple csprojects that reference eachother. When I click go to definition on a type defined in a referenced project I get a decompiled view. This issue is persisting since the very creation of c# dev kit and it is still persisting in this solution for me. Debugging steps that I already checked:

• A clean new solution => everything works fine with a clean solution
• VS 2022 => in Visual Studio go to references works fine

Steps to Reproduce

You will probably not be able to reproduce this, as I couldn't either in a new solution. I would be down to assist in debugging.

Expected Behavior

Go to definition goes to the source file of the referenced project.

Actual Behavior

Go to definition launches decompiled view of class.

Logs

C# log

2025-08-13 12:04:40.601 [info] Locating .NET runtime version 9.0.1
2025-08-13 12:04:40.617 [info] Dotnet path: C:\Program Files\dotnet\dotnet.exe
2025-08-13 12:04:40.617 [info] Activating C# standalone...
2025-08-13 12:04:46.757 [info] [stdout] {"pipeName":"\\.\pipe\a381f588"}

2025-08-13 12:04:46.757 [info] received named pipe information from server
2025-08-13 12:04:46.759 [info] client has connected to server
2025-08-13 12:04:48.113 [info] [Info - 12:04:48 PM] [Program] Language server initialized
2025-08-13 12:04:51.312 [info] [Info - 12:04:51 PM] [solution/open] [LanguageServerProjectSystem] Loading d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-backend.sln...
2025-08-13 12:04:59.371 [info] [Info - 12:04:59 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\ExtenDotNet\ExtenDotNet\ExtenDotNet.csproj
2025-08-13 12:05:07.406 [info] Detected new installation of ms-dotnettools.csdevkit
2025-08-13 12:05:09.182 [info] [Info - 12:05:09 PM] Shutting down
2025-08-13 12:05:09.190 [info] Dotnet path: C:\Program Files\dotnet\dotnet.exe
2025-08-13 12:05:09.190 [info] Activating C# + C# Dev Kit...
2025-08-13 12:05:09.757 [info] Language server process exited with 0
2025-08-13 12:05:10.203 [info] [stdout] fail: Microsoft.CodeAnalysis.Remote.ExportProviderBuilder[0]
c:\Users\up.vscode\extensions\ms-dotnettools.csharp-2.76.27-win32-x64.razorExtension\Microsoft.VisualStudioCode.RazorExtension.dll with assembly name Microsoft.VisualStudioCode.RazorExtension, Version=10.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60 conflicts with extension loaded from c:\Users\up.vscode\extensions\ms-dotnettools.csharp-2.76.27-win32-x64.razorExtension

2025-08-13 12:05:14.965 [info] [stdout] {"pipeName":"\\.\pipe\50748d1b"}

2025-08-13 12:05:14.965 [info] received named pipe information from server
2025-08-13 12:05:14.966 [info] client has connected to server
2025-08-13 12:05:15.136 [info] [Info - 12:05:15 PM] [Program] Language server initialized
2025-08-13 12:05:16.113 [info] [Info - 12:05:16 PM] [solution/open] [LanguageServerProjectSystem] Loading d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-backend.sln...
2025-08-13 12:05:29.375 [info] [Info - 12:05:29 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\cs2ts\cs2ts\cs2ts.csproj
2025-08-13 12:05:32.826 [info] [Info - 12:05:32 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\bitrix-opr\bitrix-opr.csproj
2025-08-13 12:05:33.776 [info] [Info - 12:05:33 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\officedoc-creator\officedoc-creator\officedoc-creator.csproj
2025-08-13 12:05:34.096 [info] [Info - 12:05:34 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\ConfigFramework\ConfigFramework.csproj
2025-08-13 12:05:34.300 [info] [Info - 12:05:34 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\cs2ts\cs2tsShared\cs2tsShared.csproj
2025-08-13 12:05:34.626 [info] [Info - 12:05:34 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\ExtenDotNet\ExtenDotNet\ExtenDotNet.csproj
2025-08-13 12:05:34.747 [info] [Info - 12:05:34 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-publish\myproject-publish.csproj loaded by C# Dev Kit
2025-08-13 12:05:35.602 [info] [Info - 12:05:35 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\netcorehostedservice\NetCoreHostedService\NetCoreHostedService.csproj
2025-08-13 12:05:35.602 [info] [Info - 12:05:35 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\JsonCfg.Net\JsonCfg.Net\JsonCfg.Net.csproj
2025-08-13 12:05:35.603 [info] [Info - 12:05:35 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\SourceGenerators\SourceGenerators.csproj
2025-08-13 12:05:35.603 [info] [Info - 12:05:35 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\netcorehostedservice\NetCoreHostedService\NetCoreHostedService.csproj loaded by C# Dev Kit
2025-08-13 12:05:35.619 [info] [Info - 12:05:35 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\JsonCfg.Net\JsonCfg.Net\JsonCfg.Net.csproj loaded by C# Dev Kit
2025-08-13 12:05:35.836 [info] [Info - 12:05:35 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\ConfigFramework\ConfigFramework.csproj loaded by C# Dev Kit
2025-08-13 12:05:35.839 [info] [Info - 12:05:35 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\ExtenDotNet\ExtenDotNet\ExtenDotNet.csproj loaded by C# Dev Kit
2025-08-13 12:05:36.372 [info] [Info - 12:05:36 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-backend\myproject-backend.csproj loaded by C# Dev Kit
2025-08-13 12:05:36.373 [info] [Info - 12:05:36 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-tests\myproject-tests.csproj loaded by C# Dev Kit
2025-08-13 12:05:36.645 [info] [Info - 12:05:36 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-cli\myproject-cli.csproj loaded by C# Dev Kit
2025-08-13 12:05:36.785 [info] [Info - 12:05:36 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\officedoc-creator\officedoc-creator\officedoc-creator.csproj loaded by C# Dev Kit
2025-08-13 12:05:36.786 [info] [Info - 12:05:36 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-common\myproject-common.csproj loaded by C# Dev Kit
2025-08-13 12:05:36.990 [info] [Info - 12:05:36 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\cs2ts\cs2tsShared\cs2tsShared.csproj loaded by C# Dev Kit
2025-08-13 12:05:37.037 [info] [Info - 12:05:37 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\bitrix-opr\bitrix-opr.csproj loaded by C# Dev Kit
2025-08-13 12:05:37.038 [info] [Info - 12:05:37 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\SourceGenerators\SourceGenerators.csproj loaded by C# Dev Kit
2025-08-13 12:05:37.134 [info] [Info - 12:05:37 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\cs2ts\cs2ts\cs2ts.csproj loaded by C# Dev Kit
2025-08-13 12:05:50.781 [info] [Info - 12:05:50 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-publish\myproject-publish.csproj
2025-08-13 12:05:50.890 [info] [Info - 12:05:50 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-common\myproject-common.csproj
2025-08-13 12:05:50.974 [info] [Info - 12:05:50 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-cli\myproject-cli.csproj
2025-08-13 12:05:52.700 [info] [Info - 12:05:52 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-tests\myproject-tests.csproj
2025-08-13 12:05:52.871 [info] [Info - 12:05:52 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\myproject-backend\myproject-backend.csproj
2025-08-13 12:05:52.871 [info] [Info - 12:05:52 PM] [solution/open] [LanguageServerProjectLoader] Completed (re)load of all projects in 00:00:35.5921723

C# LSP Trace Logs

Post the output from Output-->C# LSP Trace Logs here. Requires the `C#` output window log level to be set to `Trace`

Environment information

VSCode version: 1.102.3
C# Extension: 2.76.27
Using OmniSharp: false

Dotnet Information

.NET SDK: Version: 9.0.304 Commit: f12f5f689e Workload version: 9.0.300-manifests.ad61bb1c MSBuild version: 17.14.16+5d8159c5f

Runtime Environment:
OS Name: Windows
OS Version: 10.0.26100
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\9.0.304\

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
Version: 9.0.8
Architecture: x64
Commit: aae90fa090

.NET SDKs installed:
8.0.413 [C:\Program Files\dotnet\sdk]
9.0.205 [C:\Program Files\dotnet\sdk]
9.0.304 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 8.0.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 8.0.19 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 8.0.19 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.8 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
Not set

global.json file:
Not found

Learn more:
https://aka.ms/dotnet/info

Download .NET:
https://aka.ms/dotnet/download

Visual Studio Code Extensions

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angular-schematics	cyrilletuzi	6.23.0	cyrilletuzi.angular-schematics-6.23.0
Angular2	johnpapa	18.0.2	johnpapa.angular2-18.0.2
angular2-switcher	infinity1207	0.4.0	infinity1207.angular2-switcher-0.4.0
Bookmarks	alefragnani	13.5.0	alefragnani.bookmarks-13.5.0
codealignment-vscode	cpmcgrath	2.0.19	cpmcgrath.codealignment-vscode-2.0.19
copilot	GitHub	1.350.0	github.copilot-1.350.0
copilot-chat	GitHub	0.29.1	github.copilot-chat-0.29.1
csdevkit	ms-dotnettools	1.41.11	ms-dotnettools.csdevkit-1.41.11-win32-x64
csharp	ms-dotnettools	2.76.27	ms-dotnettools.csharp-2.76.27-win32-x64
dbcode	dbcode	1.14.29	dbcode.dbcode-1.14.29
docker	docker	0.14.0	docker.docker-0.14.0-win32-x64
dotnet-test-explorer	formulahendry	0.7.8	formulahendry.dotnet-test-explorer-0.7.8
gitlens	eamodio	17.3.4	eamodio.gitlens-17.3.4
hex-to-hsl	kavish	0.1.1	kavish.hex-to-hsl-0.1.1
hexeditor	ms-vscode	1.11.1	ms-vscode.hexeditor-1.11.1
jsonpath-extract	davidmarek	1.2.3	davidmarek.jsonpath-extract-1.2.3
lorem-ipsum	Tyriar	1.3.1	tyriar.lorem-ipsum-1.3.1
markdown-mermaid	bierner	1.28.0	bierner.markdown-mermaid-1.28.0
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ng-template	Angular	20.1.1	angular.ng-template-20.1.1
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VS Code version: Code 1.102.3 (488a1f239235055e34e673291fb8d8c810886f81, 2025-07-29T03:00:23.339Z)
OS version: Windows_NT x64 10.0.26100
Modes:

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CPUs	AMD Ryzen AI 7 PRO 360 w/ Radeon 880M (16 x 1996)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
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Process Argv	--crash-reporter-id 3a70d3e8-9eb1-4a73-9785-c41ead04114b
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binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
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dwoutputs:31242946
copilot_t_ci:31333650
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pythoneinst12:31285622
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pythonrdcb7:31342333
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nesew2to5:31336538
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45650338:31358607
0cj2b977:31352657
gaj49834:31362110
controlchatstate:31363048

[dibarbet]

A couple of initial things that would help

1. Your C# extension version looks a bit old, would you mind updating to the latest release (2.87.31) and seeing if its any better?
2. Can you enable trace logging and share the trace logs (see https://github.com/dotnet/vscode-csharp/blob/main/SUPPORT.md#collecting-general-logs)
3. A bit of a longshot, but if you're able to share the actual solution that reproduces it, that would be extremely helpful. You can share it privately with me (dabarbet@microsoft.com) if preferred.

I do notice something very suspicious immediately however. It looks like we're trying to load projects with both the C# standalone project loader, and CDK is also trying to load projects:

2025-08-13 12:05:29.375 [info] [Info - 12:05:29 PM] [solution/open] [LanguageServerProjectLoader] Successfully completed load of d:\Projects\myproject.opr.master\myproject\myproject-backend\lib\cs2ts\cs2ts\cs2ts.csproj

and CDK

2025-08-13 12:05:37.134 [info] [Info - 12:05:37 PM] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\Projects\myproject.opr.master\myproject\myproject-backend\lib\cs2ts\cs2ts\cs2ts.csproj loaded by C# Dev Kit

That is definitely a recipe for failure and should not be happening. Starting off with @jasonmalinowski to take a look here.