MuseScore 3.0.4 on macOS is crashing on startup.

• Feb 28, 2019 - 14:57
Reported version
P0 - Critical
S1 - Blocker

Upgraded from 3.0.2 to 3.0.4.

QtWebEngineProcess then mscore crashes moments after Start Center window opens.

Removing org.musescore.*.plist from ~/Library/Preferences/, did not help.

MacOS High Sierra 10.13.6

Attempted to attach crash logs and screen capture of crash to bug report.


Title MuseScore 3.0.4 Crashing on Startup. MuseScore 3.0.4 on Mac Crashing on Startup.
Regression No Yes
Priority P0 - Critical

In reply to by Jojo-Schmitz

Workaround No Yes

This worked for me. At first it didn't because I forgot to change the -F from the -w but once I did that it worked. Following this I went into the MuseScore preferences, turned off "Show Start Center", quit the application and reopened it normally and it worked fine.

Fix confirmed.
/Applications/MuseScore\ -w
run and open preferences, disable start center.
Temporary workaround.

Disabling Start Center in Preferences allowed me to proceed in 3.0.4, and load scores.

Playback instrumentation is working again. (Thanks!)

When I tried opening up Start Center from the File menu, it opened, and worked as expected.

I re-enabled show start center in Preferences; 3.0.4 now starts up, with Start Center, as expected.

I removed org.musescore.*.plist from ~/Library/Preferences, and restarted 3.0.4:
After going through the initial setup, Start Center opened, and software worked as expected. This was not the case when I created this report.

In summary, it seems that now after having gotten past the initial crash condition, the software is now running as expected.

Could it have been something to do with how my Start Center window had been placed in 3.0.2 (Offset to the right, with most of the web content off-screen)?

Title MuseScore 3.0.4 on macOS Crashing on Startup. MuseScore 3.0.4 on macOS is Crashing on Startup.
Severity S1 - Blocker S2 - Critical

I just updated to version 3.0.4, and the program crashes on startup every time. Can someone tell me in layman's terms how to work around this? I have several works in progress that I need to finish quickly, so this is a time sensitive issue for me. If there is a way to upload a previous version, 3.0.2 perhaps, I'd be fine with that.

Severity S2 - Critical S1 - Blocker
  1. Open any mscz/mscx file using double-click on a file (when you open a file, MuseScore doesn't show the Start Center)
  2. MuseScore should open without issues
  3. Go to Preferences...
  4. Turn the checkbox "Show Start Center on startup" off

In reply to by Jojo-Schmitz

Regression Yes No
Workaround Yes No

I tried this and it now crashes before it fully opens - it doesn't event get as far as the startcenter! I haven't yet tried the other suggestion of starting from the command line as I don't want to loose all of my set up. An early fix would be really helpful! OSX Mojave 10.14.3 and much appreciated.

Regression No Yes
Workaround No Yes

starting from the comandline using -w won't result in loosing any setup. That workaround mentioned above worked for numerous other users, sure you followed the steps?

No problem on PC, but crashing at startup on MacBook Pro. I have not been able to open version 3 to attempt suggested fixes, not even by starting from existing files.

Process: mscore [993]
Path: /Applications/MuseScore
Identifier: org.musescore.MuseScore
Version: (
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: mscore [993]
User ID: 501

Date/Time: 2019-03-01 10:50:21.685 -0500
OS Version: Mac OS X 10.14.3 (18D109)
Report Version: 12
Anonymous UUID: CF4CF606-2009-66A4-0A75-AA58A4DBC0BB

Time Awake Since Boot: 8700 seconds

System Integrity Protection: enabled

Crashed Thread: 0 CrBrowserMain Dispatch queue:

Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000004

Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [993]

Regression Yes No
Workaround Yes No

First I tried just launching a Musescore file. I didn't even see the splash screen - just the information that it Musescore had failed to start - "Musescore quite unexpectedly". Then I tried starting it with the suggested terminal command using -w. That worked fine. I closed the startcentre and then disabled it in Preferences. The only radio button ticked in Preferences was 'Start empty' and I clicked 'Apply'. Then I closed Terminal and Musescore closed too. I then restarted Musescore normally and it crashed - but I still saw the startcentre just before it crashed. In other words - I can't turn off the startcenter in Preferences. I have tried this several times, always with the same result. I see the startcentre screen every time even though it is turned off. Am I right in just closing Terminal without entering another command? Whatever, I can't get rid of the startcenter.

Thank you Jojo-Schmitz. I have no idea how to turn off the Regression and Workaround comments. I unchecked them because none of the suggested workarounds work for me - as I explained in my last comment. Looks like I will have to abandon the latest Musescore update and try and revert to an earlier version. Won't be such a bad thing as I do not like, and do not want, the Automatic Placement anyway... yes, i know, that's another subject.

Well, the title of this thread is "MuseScore 3.0.4 on macOS is Crashing on Startup." That's what I am seeing. I suppose the slight difference is that when I use the Terminal command line start and remove startcenter from the Preferences and Apply the change, the startcenter window is still just visible before the crash the next time I try to start Musescore. OSX 10.14.3 on iMac bitheway.

OK, the Terminal command line fix does work for me. I hadn't realised that the startcenter tick box was not in the main column of choices. Apologies for red herring. You were quite correct Jojo-Schmitz - thanks again for your swift replies.

I don't understand the fix of disabling the Start Center in Preferences. It doesn't stay open for more than a second before it crashes, so how do you even get to the Start Center to do this? Sorry if I am obtuse about this! I've gone back to MuseScore 2 for the meantime.

In reply to by Nevin Williams

Hey you guys! Thanx for the hint, starting Musescore with a mscz-File. After disabling the autostart of the Startcenter, Musescore seems to be working. However, after enabling the autostart of startcenter again, the application crashes immediately when starting. I hope this can be fixed.
Secondly, could you plz explain to me the meaning of the terms "regression" and "workaround"?
Thank you! (using Macos Mojave as well)

Same problem on MacOs Mojave 10.14.3!
Strange: The first time after installation it did work, but then it crashed immediately after starting.
I see that others have the same problem.It's a little consolation ;-)

It is really funny how often "Regression" and "Workaround" have been toggled between yes and no :-)
Regression: it didn't crash on startup in 3.0.3, now in 3.0.4 it does. This IS a regression, no doubt. => Yes
Workaround: of course there is no workaround which allows to use the start center on Mac in 3.0.4, but there definitely IS a workaround to use Musescore at all (e.g. double clicking .mscx file). => yes

Severity S1 - Blocker S3 - Major

MuseScore 3.0.4 .21117/ Revisiooncda4080/ Crashing at launch every time. Can't get into program. Error Message "Previous session quit unexpectedly. Restore Session? Crashes on both "yes" and "No". I'm in a loop can't get into MuseScore.

In reply to by Git Message

I’m 81 years old and don’t understand anything technical, just want my MuseScore back. Can you tell me when an update fix will be available or should I reinstall Musescore 3? MuseScore 2 was brilliant. Why break something that didn’t need fixing?

Thanks Jojo. I'm back into MuseScore 3 - your workaround fixed the problem simply and quickly. Looking forward to your next update release.

Title MuseScore 3.0.4 on macOS is Crashing on Startup. MuseScore 3.0.4 on macOS is crashing on startup.

Correct capitalisation in issue title.

Title MuseScore 3.0.4 on macOS is crashing on startup. I reinstalled the program, double clicked on a file as someone else noted, and then the file actually opened. I just disabled the splash screen as others did. This is a good workaround, thankfully.
Title I reinstalled the program, double clicked on a file as someone else noted, and then the file actually opened. I just disabled the splash screen as others did. This is a good workaround, thankfully. MuseScore 3.0.4 on macOS is crashing on startup.

Whenever I try to open Musescore an alert comes up saying "The previous session quit unexpectedly. Restore session?" It doesn't matter whether I clicked no or yes the application just closes on me.

I just downloaded 3.0.5 from (, and when I try to start it on my Mac, it crashes. It looks to me that I am intact downloading the versions which has this potential fix. How can I know for sure?

I also tried starting mscore with -F, and even that seems to crash and pop up a crash log. I'm attaching it to this comment, as well as including the shell output here in clear text.

johan:~] jnewton% /Applications/MuseScore\ -F
dyld: Symbol not found: _kSecAttrKeyTypeECSECPrimeRandom
Referenced from: /Applications/MuseScore (which was built for Mac OS X 10.12)
Expected in: /System/Library/Frameworks/Security.framework/Versions/A/Security
in /Applications/MuseScore
Trace/BPT trap

Attachment Size
mscorecrash.txt 47.79 KB
Title MuseScore 3.0.4 on macOS is crashing on startup. MuseScore 3.0.4 on macOS is crashing on startup. At home, I'm happily running the newest 3.0.x musescore.
Title MuseScore 3.0.4 on macOS is crashing on startup. At home, I'm happily running the newest 3.0.x musescore. MuseScore 3.0.4 on macOS is crashing on startup.
Regression Yes No
Reported version 3.0 3.5

MacOS Mojave 10.14.6 and MuseScore version 3.5.0. Musescore would crash shortly after launch. It was fixed by following some of the advice given above - namely UNchecking SHOW START CENTER in the MuseScore Preferences under General. (I got it to launch via Terminal using the -w option discussed above). I just wanted to add that it's the key:


in ~/Library/Preferences/org.musescore.MuseScore3.plist

That is affected. It's value is changed from TRUE to FALSE when the Preference is unchecked.

So the same could be achieved via DEFAUTS WRITE (do it with MuseScore quitted). The terminal command:

defaults write org.musescore.MuseScore3.plist ui.application.startup.showStartCenter -bool FALSE

will do that. A restart of your Mac might be a good idea following execution. Do it as the user whose MuseScore isn't working.

This is something for more advanced users. If you are unfamiliar with Terminal or preference files - try some of the other options above.

Fix version