Not authorized to access Exercises or Lectures

[Kooper16]

Describe the bug

Opening the Exercise or Lectures tab of an existing course causes a "You are not authorized to access this page." error message to appear. This message appears for all users when they have access to something (meaning if they truly don't have access to any exercise yet, then they won't see this message in the exercise tab) including Administrators.

It does not seem like we actually lost access to anything. We only get this message.

To Reproduce

1. Go to "Course Overview"
2. Click on a course with an exercise (or a lecture)
3. Click on "Exercises" (or Lectures) on the left side
4. See error

Expected behavior

No error message

Screenshots

No response

Which version of Artemis are you seeing the problem on?

7.5.5

What browsers are you seeing the problem on?

Firefox

Additional context

This started happening after upgrading from 7.5.2 to 7.5.5

Relevant log output

No response