Adjusting a note outside the range of a piano causes a crash when the piano keyboard is visible.
This bug applies to the latest release, as well as the 2.3 branch and the master branch.
Open any score, or start a new one.
Press P to show the Piano Keyboard.
Press N to enter Note Input Mode.
Click the lowest key on the Piano Keyboard to enter an A0 into the score.
Press the down arrow to move the note down a half step.
At this point, MuseScore will crash due to an array-out-of-bounds error. I have fixed this already (it was my code to begin with), and I will post a patch momentarily.