[MartinH]

Regarding the crash after a minute, I've done more testing:
- It's caused by the autosave, since disabling auto-save prevents it and setting autosave to just 5 seconds makes it happen very quickly
- It doesn't happen when exiting annotation mode
- It only happens when deleting an annotation that was pasted from the snipping tool

So a repro procedure for me:
- Enter annotation mode
- Use the snipping tool to copy and paste a piece of the score
- Make sure "allow editing of embedded pdf annotations" is enabled
- Select the copied piece of the score and delete it
- Wait a minute (assuming autosave is enabled)