If I write a Theia extension that contributes a theme, then the theme will be registered into the indexedDB as 'theia-monaco'. It works. So far, so good. If I modify my extension and remove the theme registration, my custom theme gets stuck in the DB and will remain there forever.

Workaround: run indexedDB.deleteDatabase('theia-monaco') in the devTools console.

Bug Description:

Steps to Reproduce:

1. create an extension, register a custom theme, start the app see that's it there,
2. modify your extension not to register the theme,
3. start the app; the previously added theme is still there.

Additional Information

• Operating System:
• Theia Version: 1.22.1