Bizarre saving bug.

I'm having a bizarre issue where changes to a particular part of the score do not save, even while changes to other parts of the score do.

The steps I take to get the bug:
1. In sky.mscz, at measure 38 of the voice staff, place a note at the last eighth rest in the measure.

2. Save and close the file.

3. Re-open the file

4. At this point, the note I added in step 1. is gone.

Alternatively, when I add a note to the second to last eighth rest in measure 38, save, close, and re-open I get the error: "Measure 38, staff 1 incomplete. Expected: 4/4; Found: 9/8".

I've had this error before, but I usually just mess around adding and removing measures till it doesn't come up anymore. I don't really know what causes it or how I should be fixing it.

My main question is: when I get this error, is the file completely corrupted? As in, should I be worrying about losing the data or does removing the problem measure fix any such issues?

Thank you for help.