Omnisharp crashes while loading project #8763
Description
Type: Bug
Issue Description
While loading a csproj for a .net framework 4.8 project Omnisharp.MSBuild.ProjectManager throws an exception:
[fail]: OmniSharp.MSBuild.ProjectManager
Failed to load project file 'd:\Programming\src\potw\Mod\ParahumansOfTheWormverse.csproj'.
System.AggregateException: One or more errors occurred. ---> System.MissingMethodException: Method not found: 'System.ReadOnlySpan`1<Char> Microsoft.IO.Path.GetFileName(System.ReadOnlySpan`1<Char>)'.
at Microsoft.Build.Shared.FileMatcher.IsFileNameMatch(String path, String pattern)
at System.Linq.Enumerable.WhereListIterator`1.MoveNext()
at Microsoft.Build.Shared.FileMatcher.<RemoveProjectDirectory>d__37.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Microsoft.Build.Shared.FileMatcher.GetFilesForStep(RecursiveStepResult stepResult, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory)
at Microsoft.Build.Shared.FileMatcher.GetFilesRecursive(ConcurrentStack`1 listOfFiles, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory, IList`1 searchesToExclude, Dictionary`2 searchesToExcludeInSubdirs, TaskOptions taskOptions)
at Microsoft.Build.Shared.FileMatcher.<>c__DisplayClass41_0.<GetFilesRecursive>b__0(String subdir)
at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1()
at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask)
at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at System.Threading.Tasks.Parallel.ForWorker[TLocal](Int32 fromInclusive, Int32 toExclusive, ParallelOptions parallelOptions, Action`1 body, Action`2 bodyWithState, Func`4 bodyWithLocal, Func`1 localInit, Action`1 localFinally)
at System.Threading.Tasks.Parallel.ForEachWorker[TSource,TLocal](IEnumerable`1 source, ParallelOptions parallelOptions, Action`1 body, Action`2 bodyWithState, Action`3 bodyWithStateAndIndex, Func`4 bodyWithStateAndLocal, Func`5 bodyWithEverything, Func`1 localInit, Action`1 localFinally)
at System.Threading.Tasks.Parallel.ForEach[TSource](IEnumerable`1 source, ParallelOptions parallelOptions, Action`1 body)
at Microsoft.Build.Shared.FileMatcher.GetFilesRecursive(ConcurrentStack`1 listOfFiles, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory, IList`1 searchesToExclude, Dictionary`2 searchesToExcludeInSubdirs, TaskOptions taskOptions)
at Microsoft.Build.Shared.FileMatcher.GetFilesImplementation(String projectDirectoryUnescaped, String filespecUnescaped, List`1 excludeSpecsUnescaped)
at Microsoft.Build.Shared.FileMatcher.<>c__DisplayClass67_0.<GetFiles>b__1(String _)
at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
at Microsoft.Build.Shared.FileMatcher.GetFiles(String projectDirectoryUnescaped, String filespecUnescaped, List`1 excludeSpecsUnescaped)
at Microsoft.Build.Internal.EngineFileUtilities.GetFileList(String directoryEscaped, String filespecEscaped, Boolean returnEscaped, Boolean forceEvaluateWildCards, IEnumerable`1 excludeSpecsEscaped, FileMatcher fileMatcher, Object loggingMechanism, IElementLocation includeLocation, IElementLocation excludeLocation, IElementLocation importLocation, BuildEventContext buildEventContext, String buildEventFileInfoFullPath, Boolean disableExcludeDriveEnumerationWarning)
at Microsoft.Build.Evaluation.LazyItemEvaluator`4.IncludeOperation.SelectItems(Builder listBuilder, ImmutableHashSet`1 globsToIgnore)
at Microsoft.Build.Evaluation.LazyItemEvaluator`4.LazyItemOperation.ApplyImpl(Builder listBuilder, ImmutableHashSet`1 globsToIgnore)
at Microsoft.Build.Evaluation.LazyItemEvaluator`4.LazyItemOperation.Apply(Builder listBuilder, ImmutableHashSet`1 globsToIgnore)
at Microsoft.Build.Evaluation.LazyItemEvaluator`4.LazyItemList.ComputeItems(LazyItemList lazyItemList, ImmutableHashSet`1 globsToIgnore)
at Microsoft.Build.Evaluation.LazyItemEvaluator`4.LazyItemList.GetItemData(ImmutableHashSet`1 globsToIgnore)
at System.Linq.Enumerable.<SelectManyIterator>d__17`2.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__1.MoveNext()
at Microsoft.Build.Evaluation.Evaluator`4.Evaluate()
at Microsoft.Build.Evaluation.Evaluator`4.Evaluate(IEvaluatorData`4 data, Project project, ProjectRootElement root, ProjectLoadSettings loadSettings, Int32 maxNodeCount, PropertyDictionary`1 environmentProperties, ICollection`1 propertiesFromCommandLine, ILoggingService loggingService, IItemFactory`2 itemFactory, IToolsetProvider toolsetProvider, IDirectoryCacheFactory directoryCacheFactory, ProjectRootElementCacheBase projectRootElementCache, BuildEventContext buildEventContext, ISdkResolverService sdkResolverService, Int32 submissionId, EvaluationContext evaluationContext, Boolean interactive)
at Microsoft.Build.Evaluation.Project.ProjectImpl.Reevaluate(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext)
at Microsoft.Build.Evaluation.Project.ProjectImpl.ReevaluateIfNecessary(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext)
at Microsoft.Build.Evaluation.Project.ProjectImpl.ReevaluateIfNecessary(EvaluationContext evaluationContext)
at Microsoft.Build.Evaluation.Project.ProjectImpl.Initialize(IDictionary`2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext, Boolean interactive)
at Microsoft.Build.Evaluation.Project..ctor(String projectFile, IDictionary`2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectCollection projectCollection, ProjectLoadSettings loadSettings, EvaluationContext evaluationContext, IDirectoryCacheFactory directoryCacheFactory, Boolean interactive)
at Microsoft.Build.Evaluation.ProjectCollection.LoadProject(String fileName, IDictionary`2 globalProperties, String toolsVersion)
at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore(String filePath, IReadOnlyDictionary`2 projectConfigurationsInSolution, IList`1 loggers) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectLoader.cs:line 160
at OmniSharp.MSBuild.ProjectLoader.BuildProject(String filePath, IReadOnlyDictionary`2 configurationsInSolution) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectLoader.cs:line 84
at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load(String filePath, ProjectIdInfo projectIdInfo, ProjectLoader loader, Guid sessionId, DotNetInfo dotNetInfo) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectFile\ProjectFileInfo.cs:line 117
at OmniSharp.MSBuild.ProjectManager.<>c__DisplayClass32_0.<LoadProject>b__0() in D:\a\1\s\src\OmniSharp.MSBuild\ProjectManager.cs:line 305
at OmniSharp.MSBuild.ProjectManager.LoadOrReloadProject(String projectFilePath, Func`1 loader) in D:\a\1\s\src\OmniSharp.MSBuild\ProjectManager.cs:line 316
---> (Inner Exception #0) System.MissingMethodException: Method not found: 'System.ReadOnlySpan`1<Char> Microsoft.IO.Path.GetFileName(System.ReadOnlySpan`1<Char>)'.
at Microsoft.Build.Shared.FileMatcher.IsFileNameMatch(String path, String pattern)
at System.Linq.Enumerable.WhereListIterator`1.MoveNext()
at Microsoft.Build.Shared.FileMatcher.<RemoveProjectDirectory>d__37.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Microsoft.Build.Shared.FileMatcher.GetFilesForStep(RecursiveStepResult stepResult, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory)
at Microsoft.Build.Shared.FileMatcher.GetFilesRecursive(ConcurrentStack`1 listOfFiles, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory, IList`1 searchesToExclude, Dictionary`2 searchesToExcludeInSubdirs, TaskOptions taskOptions)
at Microsoft.Build.Shared.FileMatcher.<>c__DisplayClass41_0.<GetFilesRecursive>b__0(String subdir)
at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1()
at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask)
at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)<---
---> (Inner Exception #1) System.MissingMethodException: Method not found: 'System.ReadOnlySpan`1<Char> Microsoft.IO.Path.GetFileName(System.ReadOnlySpan`1<Char>)'.
at Microsoft.Build.Shared.FileMatcher.IsFileNameMatch(String path, String pattern)
at System.Linq.Enumerable.WhereListIterator`1.MoveNext()
at Microsoft.Build.Shared.FileMatcher.<RemoveProjectDirectory>d__37.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Microsoft.Build.Shared.FileMatcher.GetFilesForStep(RecursiveStepResult stepResult, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory)
at Microsoft.Build.Shared.FileMatcher.GetFilesRecursive(ConcurrentStack`1 listOfFiles, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory, IList`1 searchesToExclude, Dictionary`2 searchesToExcludeInSubdirs, TaskOptions taskOptions)
at Microsoft.Build.Shared.FileMatcher.<>c__DisplayClass41_0.<GetFilesRecursive>b__0(String subdir)
at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1()
at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask)
at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)<---
---> (Inner Exception #2) System.MissingMethodException: Method not found: 'System.ReadOnlySpan`1<Char> Microsoft.IO.Path.GetFileName(System.ReadOnlySpan`1<Char>)'.
at Microsoft.Build.Shared.FileMatcher.IsFileNameMatch(String path, String pattern)
at System.Linq.Enumerable.WhereListIterator`1.MoveNext()
at Microsoft.Build.Shared.FileMatcher.<RemoveProjectDirectory>d__37.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Microsoft.Build.Shared.FileMatcher.GetFilesForStep(RecursiveStepResult stepResult, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory)
at Microsoft.Build.Shared.FileMatcher.GetFilesRecursive(ConcurrentStack`1 listOfFiles, RecursionState recursionState, String projectDirectory, Boolean stripProjectDirectory, IList`1 searchesToExclude, Dictionary`2 searchesToExcludeInSubdirs, TaskOptions taskOptions)
at Microsoft.Build.Shared.FileMatcher.<>c__DisplayClass41_0.<GetFilesRecursive>b__0(String subdir)
at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1()
at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask)
at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)<---
VS Community 2022 msbuild is being used:
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Located 3 MSBuild instance(s)
1: Visual Studio Community 2019 16.11.34114.132 16.11.2 - "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin"
2: Visual Studio Build Tools 2019 16.11.36602.28 16.11.6 - "C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\MSBuild\Current\Bin"
3: Visual Studio Community 2022 17.14.36202.13 17.14.10 - "C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Current\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Registered MSBuild instance: Visual Studio Community 2022 17.14.36202.13 17.14.10 - "C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Current\Bin"
The project loads fine in Visual Studio.
useModernNet is set to false.
Extension version: 2.93.22
VS Code version: Code 1.105.1 (7d842fb85a0275a4a8e4d7e040d2625abbf7f084, 2025-10-14T22:33:36.618Z)
OS version: Windows_NT x64 10.0.19045
Modes:
Logs
Environment Information
VSCode version: 1.105.1
C# Extension: 2.93.22
Using OmniSharp: true
Dotnet Information
.NET SDK: Version: 9.0.300 Commit: 15606fe0a8 Workload version: 9.0.300-manifests.af4147de MSBuild version: 17.14.5+edd3bbf37Runtime Environment:
OS Name: Windows
OS Version: 10.0.19045
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\9.0.300\
.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.
Host:
Version: 9.0.5
Architecture: x64
Commit: e36e4d1a8f
.NET SDKs installed:
5.0.416 [C:\Program Files\dotnet\sdk]
9.0.300 [C:\Program Files\dotnet\sdk]
.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.16 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.16 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.5 [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
| Extension | Author | Version | Folder Name |
|---|---|---|---|
| claude-code | Anthropic | 2.0.35 | anthropic.claude-code-2.0.35-win32-x64 |
| copilot | GitHub | 1.388.0 | github.copilot-1.388.0 |
| csharp | ms-dotnettools | 2.93.22 | ms-dotnettools.csharp-2.93.22-win32-x64 |
| debugpy | ms-python | 2025.14.1 | ms-python.debugpy-2025.14.1-win32-x64 |
| githistory | donjayamanne | 0.6.20 | donjayamanne.githistory-0.6.20 |
| python | ms-python | 2025.16.0 | ms-python.python-2025.16.0-win32-x64 |
| vscode-dotnet-runtime | ms-dotnettools | 2.3.7 | ms-dotnettools.vscode-dotnet-runtime-2.3.7 |
| vscode-pylance | ms-python | 2025.9.1 | ms-python.vscode-pylance-2025.9.1 |
| vscode-python-envs | ms-python | 1.10.0 | ms-python.vscode-python-envs-1.10.0-win32-x64 |
C# Settings
| Setting | Value |
|---|---|
| preferCSharpExtension | false |
| compilerDiagnosticScope | openFiles |
| analyzerDiagnosticScope | openFiles |
| enableXamlTools | true |
| useServerGC | true |
System Info
| Item | Value |
|---|---|
| CPUs | Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz (8 x 3600) |
| GPU Status | 2d_canvas: enabled 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 trees_in_viz: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off |
| Load (avg) | undefined |
| Memory (System) | 31.92GB (18.83GB free) |
| Process Argv | --crash-reporter-id 4bcfc64e-0dc3-46e0-afb8-7c447e4b5d27 |
| Screen Reader | no |
| VM | 0% |
A/B Experiments
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binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
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pythonrdcb7:31342333
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nes-set-on:31351930
testaa123cf:31335227
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gaj49834:31404438
cloudbuttont:31379625
todos-1:31405332
qwen_all_req:31402696
control_gpt5applypatchexclusively:31412085
3efgi100_wstrepl:31403338
trigger-command-fix:31379601
auto_model_enabled:31385282
use-responses-api:31390855
applesignin:31399435
auto_g2946222:31414244
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