Adding instruments corrupts MuseScore files

Adding empty instrument tracks (Edit > Instruments > Add To Score) can corrupt files.
In this case I was just adding empty staves for bass and drums to an existing imported .gp3 file that did not have them.
I opened the .gp3 file without trouble, added a blank stave, put nothing in the new stave and did not alter the content of the existing file in any way, then saved it. When I opened it again I got:

"Measure 53, staff 3 incomplete. Expected: 4/4; Found: 27/24
Measure 54, staff 3 incomplete. Expected: 4/4; Found: 86/48"

This is the same error I got earlier after working on a file for a while and losing my work. So I tracked it down to the adding staves that corrupted it. I hope this helps because I have seen other posts about similar problems. I have attached the original .gp3 I was using and the subsequent corrupted .mscz file for reference.
A workaround for now is open the file in TuxGuitar (a free program that is kind of like MuseScore for guitar), add the empty tracks and save, then open in MuseScore. No corruption and the empty tracks are there.