I think I got it!
I’d put my money on that it’s related with the Layer Properties window.
When you copy-paste something in “Name” and let the properties window opened, is when problems start.
Attaching a gif with the following steps.
- Moving frames, deleting layers - OK
- The same with the Properties Layer Window open - OK
- Copy the name of a layer, paste it in other one, keeping the Prop Layer window open, moving frames / deleting layers = NOT OK, aseprite freezes (depending on the amount of frames can be a long time) then error message window
- Closing the window and moving frames, deleting layers - OK again
Link to the video here:
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