Instance config may reference un-existent categories

Symptoms

About page doesn't show up and console display the following error message:

core.js:6479 ERROR Error: Uncaught (in promise): TypeError: Cannot read properties of undefined (reading 'label')
TypeError: Cannot read properties of undefined (reading 'label')
    at instance.service.ts:86

ex: https://tube-maternelle.apps.education.fr/about

Cause

A PeerTube instance may be associated with one or many categories. Config may still reference categories which were deleted afterward.

Workaround

1. Go to instance config page: https://tube-test.apps.education.fr/admin/config/edit-custom#instance-information

2. Delete referenced categories.

3. Save changes.

Resolution

Find a way to remove the related instance category when the category is deleted