Users who do not have permissions get stuck on admin loading page

[kaidesu]

Describe the issue

Users who do not have permission to view the admin control panel still get the "loading" screen, but are not subsequently redirected to an error page (permissions denied).

To reproduce

Register and sign up as a normal user. Log in, and attempt to navigate to /admin

Expected behavior

The user to be redirected to an error page, stating that they do not have the required permissions to continue.

Version and browser

Version: v6.0.0 beta 1

Bug report checklist

• I have filled out as much information as I can
• I have detailed how the issue can be reproduced
• I have searched for existing issues and to the best of my knowledge this is not a duplicate