In our work environment we have centrally managed VS Code allowed extensions via GPO.

Recently we have received a request to allow installation of an extension that is not published onto the marketplace (since the extension is only intended for internal use); all we have is the .vsix file for offline installation.

We have tried to allow the private extension via the GPO AllowedExtensions with these combinations:

1. { "publisher_id": true }
2. { "publisher_id"."extension_id": true }
3. { "extension_id": true } (The publisher_id and extension_id values are extracted from the package.json file within the .vsix package.)

When checking the extension settings page we can see the new settings being applied. However, trying to install the extension with "Install from VSIX..." resulted in the message:

Error: This extension cannot be installed because it is not in the [allowed list]

We would expect the installation would be successful. Is it something that can be done?