I am finally learning how to use the Logic Sampler. As part of a new sampler instrument I made, I created key labels. The key labels do show up in the piano roll (which apparently was not working six months ago, according to a thread I found), but when I try to save the key label set using the popup in the key label editor window, it not only won't let me save, but won't let me cancel either. Clicking 'save' or 'cancel' results in a screen flash alert, so there's no way to get out of the editor. Worse, because that save popup can't be closed, Logic won't quit. I had to force quit Logic and reopen the project to get rid of the key label editor window.
Incidentally, the key labels do seem to be automatically saved in the Sampler instrument, so saving a key label set would only be necessary if you wanted to reuse the same labels for another instrument without re-entering them.
Can anyone recreate this apparent bug?