Thanks for the reply, the above does not work. The viola staff is in channel 19 not 10 and I've checked then unchecked the drum special tab multiple times. I'm using notation 2.6.3 on a Lenovo thinkpad laptop with all current updates for windows. There is a temporary solution though, if you go to a staff (such as the timpani in my case) and change it to viola then reorder it in the staff setup tab, then it works just fine. Then just make a new timpani or whatever and it's fixed.