During installation I decided to use /repos as the location for 'location of repositories' (LOR) and Kallithea nicely scanned all my repositories in this directory. I configured other users and the review process was started. At a certain point (since this was a pilot to test kallithea for use in our organisation), I decided to change the LOR to /repo/kallithea.
After this change, all open pull request and any links to the repos throw 404 or 500 errors rather then a message saying 'this repo does not exist anymore in <LOR>'. I also wasn't offered any option to select certain repos to be moved to this new location (independently of whether this is a good thing to do or not).
Restarting and invalidating the cache did not resolve anything. The only thing that worked was changing the LOR back to the old value.