i had a file name called "014 - Supergirl & qSammy.p18628.kra" and it made my file explorer crash,it also made krita crash i think the name got created on backup i had to go into CMD to delete it I cant provide the file as trying to access it in any way makes my explorer crash.
try to zip the folder around it with 7zip maybe? It's more likely that thumbnailer has problems with the actual file, so I do need access to the file itself.
Without access to the actual file, I cannot do anything.
there was no way to get that file without crashing explorer constantly I thought maybe the naming or something coulda been a clue but i guess not
So i close the bug cause it probably cant be solved
Do you have the .kra thumbnailer installed? It might be worth it to try with it uninstalled.