Polyglot notebook stuck on installing NET interactive

[dcstevenbrixie-arch]

Describe the bug

I updated VS code a day ago. Since then, the Polyglot notebooks will not run. I get a notification that the NET Interactive version is installing. I've installed the NET 9 SDK as suggested in on-line forms. I've restarted my computer multiple times, un-installed and installed the extension. It's not working.
Here's the version of VS Code:
Version: 1.108.1 (system setup)
Commit: 585eba7c0c34fd6b30faac7c62a42050bfbc0086
Date: 2026-01-14T14:55:44.241Z
Electron: 39.2.7
ElectronBuildId: 12953945
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26200

Please complete the following:

Which version of .NET Interactive are you using? (In a notebook, run the #!about magic command. ):

• OS
  • [x ] Windows 11
  • Windows 10
  • macOS
  • Linux (Please specify distro)
  • iOS
  • Android
• Browser
  • [x ] Chrome
  • Edge
  • Firefox
  • Safari
• Frontend
  • Jupyter Notebook
  • Jupyter Lab
  • nteract
  • [x ] Visual Studio Code
  • Visual Studio Code Insiders
  • Visual Studio
  • Other (please specify)

Screenshots

If applicable, please add screenshots of the entire VS Code window.

[CapAbleMirek]

Just had the same issue.

I had to downgrade Polyglot Notebooks extension to version
1.0.6323010

and disable auto updates.
The latest version released yesterday hangs during installation.

[rmves]

I also have the same issue. Here is the diagnotic output I see in VS Code

Extension started for VS Code Stable.
create-tool-manifest: Executing [dotnet new tool-manifest] in 'c:\Users%USER%\AppData\Roaming\Code\User\globalStorage\ms-dotnettools.dotnet-interactive-vscode'.
create-tool-manifest: Finished with code 0.
create-tool-manifest: STDOUT:
The template "Dotnet local tool manifest file" was created successfully.
tool-uninstall: Executing [dotnet tool uninstall Microsoft.dotnet-interactive] in 'c:\Users%USER%\AppData\Roaming\Code\User\globalStorage\ms-dotnettools.dotnet-interactive-vscode'.
tool-uninstall: Finished with code 1.
tool-uninstall: STDERR:
Cannot find a manifest file that contains package id 'microsoft.dotnet-interactive'.
tool-install: Executing [dotnet tool install --add-source https://api.nuget.org/v3/index.json --ignore-failed-sources Microsoft.dotnet-interactive --version 1.0.707101] in 'c:\Users%USER%\AppData\Roaming\Code\User\globalStorage\ms-dotnettools.dotnet-interactive-vscode'.
tool-install: Finished with code 1.
tool-install: STDERR:
Unhandled exception: Settings file 'DotnetToolSettings.xml' was not found in the package.
Error acquiring dotnet-interactive tool: undefined

[dimontei]

I faced the same issue, tried to install .net 9 SDK no luck, tried to use an old Polyglot version and worked.

[jonsequitur]

Do you have .NET 10 installed? The latest release requires it.

[DawMatt]

Do you have .NET 10 installed? The latest release requires it.

@jonsequitur, Why do you say that? The extension marketplace page doesn't seem to support that statement, indicating only .NET 9 is required. Below is copied direct from the extension page.

Getting Started

1. Install the latest Visual Studio Code.
2. Install the latest .NET 9 SDK.
3. Install the Polyglot Notebooks extension from the marketplace.

[DawMatt]

OK, a number of recent commits in this repo appear to be moving dotnet-interactive across to .NET 10 SDK, but the latest released version in the repo is dotnet-interactive v1.0.6160010 and the latest extension version is trying to install v1.0.707101.

Even though v1.0.707101 doesn't seem to be officially released yet, the released version of Polyglot is trying to use it and having trouble installing it. Is something to do with the dotnet-interactive release process for the new version causing this issue?

UPDATE:
After installing .NET 10 SDK and restarting VS Code, this problem has been resolved for me.

It is unclear why the dotnet-interactive install failed to detect the missing dependency, and why the install notification chose to continue running indefinitely. Disclosing the failure and providing some useful feedback about the issue, and how to resolve it, would seem to be a better approach.

[alexeig]

UPDATE: After installing .NET 10 SDK and restarting VS Code, this problem has been resolved for me.

Ditto, installing .NET 10.0 SDK resolved the same issue for me. Thank you. (2nd having this issue and fairly sure that last time I had to manually install .Net 9.0 SDK, as well.)

[jonsequitur]

It is unclear why the dotnet-interactive install failed to detect the missing dependency, and why the install notification chose to continue running indefinitely.

The dotnet-interactive tool depends on a specific .NET SDK version and uses NuGet for acquisition, which unfortunately causes install to fail unless you have that SDK version installed. This is definitely a bug.