Pasting a partial measure of a single voice to measure without that voice corrupts score.
OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 184.108.40.2068021803, revision: 3224f34
Frequency: always reproducible (IMO, so easy, no example file necessary)
Case: Copy one or more notes of a single voice, other than voice 1, and paste into one or more measures in which the pasted voice is not present.
Result: If the copied notes do not end on a measure boundary (the length of the copied music is not a multiple of a measure), the pasted voice is not extended (padded) to fill the last measure. If the score is saved and reloaded, MuseScore complains about the measure.
To reproduce the issue:
1) Copy part of a measure including voice 2, 3, or 4 (not including voice 1!),
2) Select a measure that only has voice 1 and paste that which was copied.
Carefully examine the voice that was pasted. The pasted voice was not padded with rests to fill the measure.
I first noticed this copying a Drumset part (Voice 2 is used for feet and a little more) where I copied a partial measure and only got the rests for voice 1.
* Create the additional voice before pasting (Tools->Voice->...).
* Use the Voice tools to switch the partial voice to Voice 1. I've had this work, but I also had a case where I was unable to switch the voice and had to undo the paste and use the other method.