Note input/editing is extremely slow

• Dec 11, 2020 - 03:49
Reported version
S2 - Critical
needs info

No matter what size score I open (even with one instrument and only a few measures), note input and editing are extremely slow, with almost a second of delay every time I hit a key. It happens on every single score no matter the size and no matter how many scores I have open. This is a new problem, and I both reset to factory settings and downloaded the latest update to try and fix it and nothing has worked. I am not using a MIDI keyboard or adding any soundfonts or doing anything besides just using the program in the most basic way, and suddenly it is extremely slow. Running on MacOS. I've seen people complaining about similar problems with musescore 3 but no fixes that work for me. Please help!


I don't know if you have something similar to Windows task manager on Mac that would tell you all of the programs you have running at the same time. If you have a bunch of other things running it might cause the problem.

Even if you think it happens to all scores, it could still be they have something in common., So posting one such score would help in understanding if the problem is in MuseScore itself or perhaps some interaction between it and something else on your system in particular.

In reply to by Marc Sabatella

I had the same problem and solved it by opening the lagging score in the version contained in the Musescore back-up folder. You do this with the lagging score open, then click File, then click Open and find the same score in the Musescore drop-down menu (which is apparently a back-up folder) and open it. This file version was not slow for me. When I returned to the slow score, a warning appeared identifying a corrupted bar. This notice hadn't appeared before. When I deleted the corrupted bar in the slow score, the formerly slow score was working fine again. Perhaps the problem is due to corrupted bars that the system has not fully understood or identified, and this causes a general freezing?

I have the same issue with all of my scores that I had started in MuseScore 3 and am now opening them in 4. See attached segment. The lag between striking a note on the MIDI keyboard and the note sounding and being entered into the score is about 1 second.

Attachment Size
currupted?.mscz 25.48 KB