Comment 51 for bug 402892

I discovered a way to consistently trigger this. I don't know if all these steps are necessary, but it works for me consistently this way.

Configuration:
- Ubuntu MATE 20.10
- caja version 1.24.0
- Evolution version 3.38.1-1

Steps to Reproduce:
1. In Evolution, open the 'Compose Message' window. I have it set by default to 'Plain Text' editing mode, and attachment bar collapsed.
2. Open caja and navigate to the desired file.
3. drag & drop the file in the message body. This should result in the full file path URI being displayed as the message.
4. press `CTRL+Z` (Undo).
5. Now drag the same file again, over the message body, into the (collapsed) attachment bar.
6. Your mouse should now be stuck in DND mode, requiring `pkill caja` to release it.