[Acc 10.4.0pr1, HP Pavilion g6-2306el, Win8.1]
Here are the steps to try and reproduce this bug (At least this was what I was working on when the program crashed, and it happens every time I repeat these steps):
1. Open the LXX1 module.
2. Search for 1 Chr 26:6.
3. Highlight the text.
4. Select "Languages-->Diagram" from the toolbar.
5. Drag across the first four greek words to group them.
6. Move the group below the rest.
7. Click outside of the group.