Hey Crinrict!
I already deleted the exceptions BUT I accidentally seemed to fix the problem. The gallery is still not the way it was, I'm still having the same problems as shown below by other commenters. The gallery search is broken, it shows very little results or none at times and search filters stop working, so it does not for example show "most popular" results at all.
But my main problem, the gallery not working altogether, had probably something to do with onedrive. I found some old folders in program files that had synced up into onedrive and when I cleaned up those files, the gallery stopped spawning lastexceptions.
But thanks for your help, if there are future problems, I will remember to use third party sites for lastexceptions!