Hello Djim,

I was able to reproduce the problem you reported in Composer 2.5:

1. Open a MIDI file.
2. Choose the Setup command in the Staff menu.
3. Select a non-drum staff.
4. Try to add a checkmark to the Drum Instrument [ ] checkbox.

Indeed, Composer 2.5 hangs at this point.

I'll fix this soon in a Composer 2.5.1 maintenance release. The problem was newly introduced in Composer 2.5; it is not a bug in 2.4.2.

For now, you can easily work around the problem. Instead of using the Setup command in the Staff menu, use the Staff Setup button that is displayed when you choose View / Staff Controls. The resulting "single staff setup" dialog box also has a Drum Instrument [ ] check box, and it works without any problem.

Thanks for reporting this problem, Djim!

[Note to myself and Sherry: task #1784]

Cheers
-- Mark