Aseprite v1.3-beta14 on steam
Platform: Windows 10
When you have the cel properties window open when either deleting a range of cels or moving a range of cels onto cels with content already in them, it brings up the “problem has occurred window” repeatedly.
It does not happen when you move cels into empty cels.
The more cels you overwrite / delete at once, the more the window pops up.
You can’t close aseprite while it’s happening so if a lot is moved / changed it’s quicker to kill it in the task manager.