C# Dev Kit: Solution Explorer shows only Dependencies node — no source files in any project (v3.11.200)

[lancione3]

Environment data

dotnet --info output:

.NET SDK:
 Version:           10.0.201
 Commit:            4d3023de60
 Workload version:  10.0.200
 MSBuild version:   18.3.0-release-26153-122+4d3023de6

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  26.1
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/10.0.201/

C# logs

C# output window contents:
server.diagnostic.log — Solution loads successfully with all 227 projects:

EnvironmentState update ver=0 sln=0 folder=0 projects=0
EnvironmentState update ver=1 sln=1 folder=1 projects=227

C# Dev Kit.log — No errors during solution open or restore:

Completed processing the solution file "…/<file>.slnx" in Dev Kit server (8121ms)
Selected configuration: <Default>, active configuration: Debug|Any CPU
Completed Restoring NuGet packages (24652ms)
Completed Query for all projects (30833ms)

ProjectTreeProvider log — Every getChildren call returns empty items. This repeats for every project:

Start : getChildren
Stop : getChildren
Microsoft.VisualStudio.ProjectSystem.ProjectTreeProvider write:
  jsonrpc 2.0 result { items: [] , error: null }

New Item *Dependencies
OnTreeCollectionReset …

Start : getChildren
Stop : getChildren
Microsoft.VisualStudio.ProjectSystem.ProjectTreeProvider write:
  jsonrpc 2.0 result { items: [{ NodeType: "Virtual", Name: "Dependencies" }] , error: null }

No source files are ever returned — only the Dependencies virtual node.

Steps to reproduce

1. Install C# Dev Kit 3.11.200 (upgraded from 3.10.14)
2. Open a workspace with an .slnx solution containing SDK-style projects targeting net10.0
3. Let the solution load and NuGet restore complete
4. Expand any project in the Solution Explorer
5. Observe that only the "Dependencies" node appears — no source files or folders

Expected behavior

Source files and folders should appear under each project in the Solution Explorer, as they did in C# Dev Kit 3.10.14.

Actual behavior

Every project in the Solution Explorer shows only a "Dependencies" virtual node. All source files, folders, and other items are missing from the tree. This affects all 227 projects uniformly.

Additional context

• Previous working version: C# Dev Kit 3.10.14 — rolling back to this version restores the expected behavior.
• Solution format: .slnx (XML-based solution file)
• The problem is not project-specific. All projects are standard SDK-style .csproj files, e.g.:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <Configurations>Debug;Release</Configurations>
  </PropertyGroup>
  <ItemGroup>
    <ProjectReference Include="..\<ProjectName>\<ProjectName>.csproj" />
  </ItemGroup>
</Project>

• Clearing cached state (~/Library/Application Support/Code/User/globalStorage/ms-dotnettools.csdevkit and workspace storage) did not resolve the issue.
• .NET: Restart Language Server and Developer: Reload Window did not resolve the issue.