"Insufficient Permission" when accessing a course

It can happen that you have access to a course with your Bitesize Irish membership (it's listed in colour on Aistear), but once you click on it you either see:

A message saying that you have insufficient permission, that your membership doesn't cover that course
Or you're brought back to the login page, and you're stuck in a loop.

Clearing your browser's site cache can be the resolution to this issue.

Clearing your cache

Chrome Desktop users

Visit chrome://settings/content/all?searchSubpage=aistear in Chrome
You should see bitesize.irish listed. Expand that section.
In the expanded list, you should see aistear.bitesize.irish. Click the trash icon next to this in order to clear the site's settings.
Now that your site cache is cleared, you can go back to https://aistear.bitesize.irish/