Increasing the duration of multiple notes causes crash
Steps to reproduce:
1) Open any of the example scores.
2) Select all.
3) Increase the duration (for example, add an augmentation dot or change to quarter or half note).
MuseScore does not crash. (See notes.)
MuseScore crashes. (Except for score B, when changing to quarter notes.)
For scores A and B (at least for adding an augmentation dot or increasing to quarter notes) I would generally expect the behavior to be the same as that which occurs when one replaces step 2) by '2a) Right-click on a note and choose "Select > All Similar Elements".' Namely, the notes increase their lengths to the requested duration, preserving their start times. This is consistent with what happens when you decrease the durations.
However, if the new notes would overlap, the 'right' behavior ceases to be clear to me. In fact, one could argue that the semantics should be to increase the rest durations as well as the note durations, in which case the 'right' behavior is unclear for all of the cases.
For smaller selections (how much smaller depends on the score and the chosen duration), MuseScore does not crash; however, it still behaves rather strangely. For non-dotted durations, the only duration of the first note changes, pushing the rest of the selection right and removing any pre-existing notes that those note would overlap with. For dotted (or multiply-dotted) durations, the results are pretty weird (try selecting the first measure in score A and adding triple augmentation dots). (Neither of these is consistent with what happens if you select only the notes.)
OS: macOS 10.15, Arch.: x86_64, MuseScore version (64-bit): 188.8.131.52537, revision: 43c5553
OS: macOS 10.15, Arch.: x86_64, MuseScore version (64-bit): 184.108.40.206047, revision: f4c0004
OS: macOS 10.15, Arch.: x86_64, MuseScore version (64-bit): 220.127.116.11069, revision: 81b3238
A typical crash log is attached (from the first version listed).