Crash when changing Time Signature in parts

• Jan 20, 2019 - 10:10
Reported version
P0 - Critical
S2 - Critical

OS: macOS 10.14, Arch.: x86_64, MuseScore version (64-bit):, revision: 06a66a2

Steps to reproduce:

  1. Open MuseScore3
  2. Create New Score
  3. choose "Jazz Lead Sheet"
  4. Add instrument "bass guitar"
  5. Parts: make all
  6. Go into bass part.
  7. Change style to turn off multi-part rests
  8. Add Time Signature 3/4 to bar 2
  9. boom

It does not happen if the time signature change is added to the main tab, only the part. That's the workaround.


I can confirm the crash, it happens in breakCrossMeasureBeams(), in measure 20 (!), because the measure seems completely empty, no rests or anything. Only thing I can think about that measure that would be special is that might be where the line break occurred, as this was the case for #282503: Spurious line break after removal of line break on previous system. Would seem unexpected if these two apparently unrelated bugs turned out to have the same cause, but you never know.

Very bad things here (well, more or less expected since you get crashes)
Nevertheless, for example:

1) SATB template (entire, or with a few measures)
2) Create parts
3) In Soprano part: insert a 2/4 time signature
4) Toggle in other part let's say Alto (press M to disable mm rests)

Result: caracterized last measure corrupt, and very bad corruption (0/1) in parts, and on Save, in the entire score. See the test file: satb time sig parts.mscz

Really critical.

After checking, and in the scenario just above, I observe a change on August 14, 2018.

  • As expected with d56efb5
  • And things turn wrong with a7a1a56
    (nothing obvious at first glance - there is another commit between them - at least about time sig only)
Status closed active
Reported version 3.0 3.5
Workaround Yes No

I am finding this same issue, when I attempt to change a time signature, Musescore crashes. My score is a scanned PDF which I am now trying to correct the scanning errors of. So parts are already fully created but the time signature change has not been recognised during the scan, so I want to add it in. I don't fully understand the replies here to know if someone has found a solution?

Fix version