VSCode: CodeLens references numbers did not load and the output window contain error "Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object." when doing the Razor refactoring

Azure DevOps work item: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1284417

Testcases Affected

[6.0] SimpleWebAppRazorEditingWithVSCode [6.0] SimpleBlazorRazorEditingWithVSCode

Platform

[x] Windows
[x] macOS
[ ] Linux

Repro Steps

Create an MVC project and open via VS Code:
```
md MVC
cd MVC
dotnet new mvc
code .
```
Go to https://github.com/OmniSharp/omnisharp-vscode/releasesinstall the latest csharp-1.23.10-lsp-beta.vsix.
Open Pages/Shared/_Layout.cshtml
Type "@add" and verify the intellisense list. Select "addTagHelper", then type "*, Microsoft.AspNetCore.Mvc.TagsHelpers" following it. Save the change.
In VS Code, using CTRL + ~ to open up TERMINAL window, type the following code.
```
'namespace MVC // Or Razor
{
public class CustomTagHelper
{
}
}' | Out-File CustomTagHelper.cs
```
1. In CustomTagHelper.cs, type ": TagHelper" following the class. And then select "using Microsoft.AspNetCore.Razor.TagHelpers" through the Quick Actions
2. In _Layout.cshtml, type "@addTagHelper *, MVC
3. Open Program.cs, then enter the code: public interface ICheese {} above public class Program and save
4. Edit Index.cshtml to include the following at the bottom:
```
@{ var x = typeof(Program); }
@functions {
public class Cheddar : ICheese {}
}
```
Save and close Index.cshtml
Close all instances of VSCode and re-open this project.
go to the program.cs file

Note:

It works well on 5.0 Project
It works well on 6.0 Preview 1

Actual Result

CodeLens references numbers did not load and the output window contain error "Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object."

Error Log

Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object.

at OmniSharp.Helpers.LocationExtensions.<>c__DisplayClass0_0.b__3(Document d) in D:\a\1\s\src\OmniSharp.Roslyn.CSharp\Helpers\LocationExtensions.cs:line 45

at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable1 source, Func2 predicate)

at OmniSharp.Helpers.LocationExtensions.g__GetSourceText|0_0(Location location, IEnumerable`1 documents, Boolean hasMappedPath) in D:\a\1\s\src\OmniSharp.Roslyn.CSharp\Helpers\LocationExtensions.cs:line 45

at OmniSharp.Helpers.LocationExtensions.GetQuickFix(Location location, OmniSharpWorkspace workspace) in D:\a\1\s\src\OmniSharp.Roslyn.CSharp\Helpers\LocationExtensions.cs:line 19

at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()

at System.Linq.Enumerable.d__64`1.MoveNext()

at System.Linq.Buffer1..ctor(IEnumerable1 source)

at System.Linq.OrderedEnumerable`1.d__1.MoveNext()

at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IEnumerable values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)

at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)

at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)

at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)

at Newtonsoft.Json.JsonConvert.SerializeObjectInternal(Object value, Type type, JsonSerializer jsonSerializer)

at OmniSharp.Protocol.Packet.ToString() in D:\a\1\s\src\OmniSharp.Host\Protocol\Packet.cs:line 22

at System.IO.TextWriter.WriteLine(Object value)

at System.IO.TextWriter.SyncTextWriter.WriteLine(Object value)

at OmniSharp.Services.SharedTextWriter.ProcessWriteQueue() in D:\a\1\s\src\OmniSharp.Host\Services\SharedTextWriter.cs:line 48

at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)

at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)

at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

at System.Threading.ThreadHelper.ThreadStart()

We ran into this issue on Mac/Linux with latest .NET 6.0 Preview 3 build and there are some fail logs as following and check "https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1284417" for more details

We ran into this issue in the latest .NET 6.0 Preview 3 build when opening the Program.cs file or reopening the project. And there are some logs as following and check here for more details.

@captainsafia @pranavkm I imagine the source generator bit failing in O# is expected?

Nope -- I haven't seen this before. The only O# related issues we're tracking at the moment occur after the source generators are loaded.

I'm not familiar with how O#'s semantics for loading generators/analyzers differ from VS or the compiling on the CLI so I don't have any hypothesis to this end.

This issue still repro on the latest csharp-1.23.11.vsix, and there appears a "MISSING command" , when click it , says "command missing not found"

The source generator error might suggest that it's because the Razor one is referencing too new a source generator version. By too new, it's the same version as the compiler in the SDK, but O# hasn't picked it up.

Perhaps we should consider pinning this version here: https://github.com/dotnet/sdk/blob/main/src/RazorSdk/SourceGenerators/Microsoft.NET.Sdk.Razor.SourceGenerators.csproj#L15 rather than have it float.

@pranavkm Hmmm. Is there a way for us to know what is considered "too new" my O#?

I'm thinking about scenarios where we want to pick up the most recent version to get a bug fix (like the issues with special characters in filenames) or if we're consuming a new API. It seems a little weird to downgrade for the sake of O# in those scenarios.

The version of the compiler that is referenced by the source generator shouldn't generally matter since you ultimately get the version that it's loaded in. We can target a minimum version that supports all the features we need (for e.g. when we get incremental source generators we can update).

That said it's possible that the reported issue is a point in time issue that goes away once O# is updated. Maybe @JoeRobich might be able to help us understand this better?

That said it's possible that the reported issue is a point in time issue that goes away once O# is updated. Maybe @JoeRobich might be able to help us understand this better?

Agreed. I haven't seen this pop up in a project I'm working on with the latest C# extension.

Starting OmniSharp server at 4/13/2021, 8:10:34 PM
    Target: /Users/captainsafia/Verifications/RerenderExplorations

OmniSharp server started.
    Path: /Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/run
    PID: 66842

[info]: OmniSharp.Stdio.Host
        Starting OmniSharp on MacOS 11.2.3 (x64)
[info]: OmniSharp.Services.DotNetCliService
        DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Located 1 MSBuild instance(s)
            1: StandAlone 16.9.0 - "/Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/omnisharp/.msbuild/Current/Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        MSBUILD_EXE_PATH environment variable set to '/Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/omnisharp/.msbuild/Current/Bin/MSBuild.exe'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: StandAlone 16.9.0 - "/Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/omnisharp/.msbuild/Current/Bin"
            CscToolExe = csc.exe
            MSBuildToolsPath = /Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/omnisharp/.msbuild/Current/Bin
            CscToolPath = /Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/omnisharp/.msbuild/Current/Bin/Roslyn
            BypassFrameworkInstallChecks = true
            MSBuildExtensionsPath = /Users/captainsafia/.vscode/extensions/ms-dotnettools.csharp-1.23.11/.omnisharp/1.37.8/omnisharp/.msbuild
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.Completion.CompletionOptionsProvider, Order: 0
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.ImplementTypeWorkspaceOptionsProvider, Order: 110
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.BlockStructureWorkspaceOptionsProvider, Order: 140
[info]: OmniSharp.Cake.CakeProjectSystem
        Detecting Cake files in '/Users/captainsafia/Verifications/RerenderExplorations'.
[info]: OmniSharp.Cake.CakeProjectSystem
        Could not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
        Skip loading projects listed in solution file or under target directory because MsBuild:LoadProjectsOnDemand is true.
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in '/Users/captainsafia/Verifications/RerenderExplorations'.
[info]: OmniSharp.Script.ScriptProjectSystem
        Could not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
        Configuration finished.
[info]: OmniSharp.Stdio.Host
        Omnisharp server running using Stdio at location '/Users/captainsafia/Verifications/RerenderExplorations' on host 66764.
[info]: OmniSharp.OmniSharpWorkspace
        Miscellaneous file: /Users/captainsafia/Verifications/RerenderExplorations/Shared/MainLayout.razor__virtual.cs added to workspace
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for '/Users/captainsafia/Verifications/RerenderExplorations/RerenderExplorations.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: /Users/captainsafia/Verifications/RerenderExplorations/RerenderExplorations.csproj
[info]: OmniSharp.MSBuild.ProjectManager
        Successfully loaded project file '/Users/captainsafia/Verifications/RerenderExplorations/RerenderExplorations.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
        Adding project '/Users/captainsafia/Verifications/RerenderExplorations/RerenderExplorations.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Update project: RerenderExplorations
[info]: OmniSharp.Roslyn.CSharp.Services.Diagnostics.CSharpDiagnosticWorkerWithAnalyzers
        Solution initialized -> queue all documents for code analysis. Initial document count: 10.

The version of the compiler that is referenced by the source generator shouldn't generally matter since you ultimately get the version that it's loaded in. We can target a minimum version that supports all the features we need (for e.g. when we get incremental source generators we can update).

That said it's possible that the reported issue is a point in time issue that goes away once O# is updated. Maybe @JoeRobich might be able to help us understand this better?

Our current release moved us from using Roslyn 3.9 to 3.10, which is why the error went away.

The NRE from this issue seems to be the same as https://github.com/OmniSharp/omnisharp-roslyn/issues/2125

I have tried this issue in the latest .Net 6.0(Its specific version information is here), and it still reproduces.This is the latest error log as following:

Error Log

Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object at OmniSharp.Helpers.LocationExtensions+<>c.b0_2 (Microsoft.CodeAnalysis.Document document) [0x00000] in :0 at System.Linq.Utilities+<>c__DisplayClass2_0`3[TSource,TMiddle,TResult].b0 (TSource x) [0x00012] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable+SelectArrayIterator2[TSource,TResult].ToArray () [0x00012] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable1[T] source) [0x0001f] in <17e8581c65f940ca8137dd67206f5dbd>:0 at OmniSharp.Helpers.LocationExtensions.GetQuickFix (Microsoft.CodeAnalysis.Location location, OmniSharp.OmniSharpWorkspace workspace) [0x00128] in :0 at OmniSharp.Roslyn.CSharp.Services.Navigation.FindUsagesService+<>cDisplayClass3_0.b2 (Microsoft.CodeAnalysis.Location l) [0x00000] in :0 at System.Linq.Enumerable+SelectEnumerableIterator2[TSource,TResult].MoveNext () [0x00048] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Set1[TElement].UnionWith (System.Collections.Generic.IEnumerable1[T] other) [0x00018] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable+DistinctIterator1[TSource].FillSet () [0x0000b] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable+DistinctIterator1[TSource].ToArray () [0x00000] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Buffer1[TElement]..ctor (System.Collections.Generic.IEnumerable1[T] source) [0x0000a] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.OrderedEnumerable1+d3[TElement].MoveNext () [0x0001e] in <17e8581c65f940ca8137dd67206f5dbd>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList (Newtonsoft.Json.JsonWriter writer, System.Collections.IEnumerable values, Newtonsoft.Json.Serialization.JsonArrayContract contract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract collectionContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000e1] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonContract valueContract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract containerContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000d6] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonObjectContract contract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract collectionContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x0008d] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonContract valueContract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract containerContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000b2] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonObjectContract contract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract collectionContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x0008d] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonContract valueContract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract containerContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000b2] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize (Newtonsoft.Json.JsonWriter jsonWriter, System.Object value, System.Type objectType) [0x00079] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonSerializer.SerializeInternal (Newtonsoft.Json.JsonWriter jsonWriter, System.Object value, System.Type objectType) [0x0023a] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonSerializer.Serialize (Newtonsoft.Json.JsonWriter jsonWriter, System.Object value, System.Type objectType) [0x00000] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonConvert.SerializeObjectInternal (System.Object value, System.Type type, Newtonsoft.Json.JsonSerializer jsonSerializer) [0x00028] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonConvert.SerializeObject (System.Object value, System.Type type, Newtonsoft.Json.JsonSerializerSettings settings) [0x00007] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonConvert.SerializeObject (System.Object value) [0x00000] in <2676a2da6edc420e890ed28aa4572ee5>:0 at OmniSharp.Protocol.Packet.ToString () [0x00000] in <8b570aa16fd64ee18069d430196dac2b>:0 at System.IO.TextWriter.WriteLine (System.Object value) [0x00028] in :0 at System.IO.TextWriter+SyncTextWriter.WriteLine (System.Object value) [0x00000] in :0 at (wrapper synchronized) System.IO.TextWriter+SyncTextWriter.WriteLine(object) at OmniSharp.Services.SharedTextWriter.ProcessWriteQueue () [0x0001d] in <8b570aa16fd64ee18069d430196dac2b>:0 at System.Threading.ThreadHelper.ThreadStart_Context (System.Object state) [0x00014] in :0 at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00071] in :0 at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00000] in :0 at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) [0x0002b] in :0 at System.Threading.ThreadHelper.ThreadStart () [0x00008] in :0 [ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object at OmniSharp.Helpers.LocationExtensions+<>c.b0_2 (Microsoft.CodeAnalysis.Document document) [0x00000] in :0 at System.Linq.Utilities+<>cDisplayClass2_03[TSource,TMiddle,TResult].<CombineSelectors>b__0 (TSource x) [0x00012] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable+SelectArrayIterator2[TSource,TResult].ToArray () [0x00012] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x0001f] in <17e8581c65f940ca8137dd67206f5dbd>:0 at OmniSharp.Helpers.LocationExtensions.GetQuickFix (Microsoft.CodeAnalysis.Location location, OmniSharp.OmniSharpWorkspace workspace) [0x00128] in :0 at OmniSharp.Roslyn.CSharp.Services.Navigation.FindUsagesService+<>c__DisplayClass3_0.b2 (Microsoft.CodeAnalysis.Location l) [0x00000] in :0 at System.Linq.Enumerable+SelectEnumerableIterator2[TSource,TResult].MoveNext () [0x00048] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Set1[TElement].UnionWith (System.Collections.Generic.IEnumerable1[T] other) [0x00018] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable+DistinctIterator1[TSource].FillSet () [0x0000b] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Enumerable+DistinctIterator1[TSource].ToArray () [0x00000] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.Buffer1[TElement]..ctor (System.Collections.Generic.IEnumerable1[T] source) [0x0000a] in <17e8581c65f940ca8137dd67206f5dbd>:0 at System.Linq.OrderedEnumerable1+d__3[TElement].MoveNext () [0x0001e] in <17e8581c65f940ca8137dd67206f5dbd>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList (Newtonsoft.Json.JsonWriter writer, System.Collections.IEnumerable values, Newtonsoft.Json.Serialization.JsonArrayContract contract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract collectionContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000e1] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonContract valueContract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract containerContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000d6] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonObjectContract contract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract collectionContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x0008d] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonContract valueContract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract containerContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000b2] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonObjectContract contract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract collectionContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x0008d] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter writer, System.Object value, Newtonsoft.Json.Serialization.JsonContract valueContract, Newtonsoft.Json.Serialization.JsonProperty member, Newtonsoft.Json.Serialization.JsonContainerContract containerContract, Newtonsoft.Json.Serialization.JsonProperty containerProperty) [0x000b2] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize (Newtonsoft.Json.JsonWriter jsonWriter, System.Object value, System.Type objectType) [0x00079] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonSerializer.SerializeInternal (Newtonsoft.Json.JsonWriter jsonWriter, System.Object value, System.Type objectType) [0x0023a] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonSerializer.Serialize (Newtonsoft.Json.JsonWriter jsonWriter, System.Object value, System.Type objectType) [0x00000] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonConvert.SerializeObjectInternal (System.Object value, System.Type type, Newtonsoft.Json.JsonSerializer jsonSerializer) [0x00028] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonConvert.SerializeObject (System.Object value, System.Type type, Newtonsoft.Json.JsonSerializerSettings settings) [0x00007] in <2676a2da6edc420e890ed28aa4572ee5>:0 at Newtonsoft.Json.JsonConvert.SerializeObject (System.Object value) [0x00000] in <2676a2da6edc420e890ed28aa4572ee5>:0 at OmniSharp.Protocol.Packet.ToString () [0x00000] in <8b570aa16fd64ee18069d430196dac2b>:0 at System.IO.TextWriter.WriteLine (System.Object value) [0x00028] in :0 at System.IO.TextWriter+SyncTextWriter.WriteLine (System.Object value) [0x00000] in :0 at (wrapper synchronized) System.IO.TextWriter+SyncTextWriter.WriteLine(object) at OmniSharp.Services.SharedTextWriter.ProcessWriteQueue () [0x0001d] in <8b570aa16fd64ee18069d430196dac2b>:0 at System.Threading.ThreadHelper.ThreadStart_Context (System.Object state) [0x00014] in :0 at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00071] in :0 at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) [0x00000] in :0 at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) [0x0002b] in :0 at System.Threading.ThreadHelper.ThreadStart () [0x00008] in :0

@NTaylorMullen This issue does not reproduce after installing the pre-release C# (here). Should we close it ？

@NTaylorMullen This issue does not reproduce after installing the pre-release C# (here). Should we close it ？

Oh definitely! Thanks for double checking @v-Lily!

dotnet / razor

VSCode: CodeLens references numbers did not load and the output window contain error "Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object." when doing the Razor refactoring #4318