MuseScore crashes during start-up while displaying "Start center"

• Sep 3, 2018 - 10:22
Reported version
P1 - High
S3 - Major

The latest version of the Dev. version master crashes on my windows system. Tested with the versions from 31.08. and 1.9.
The crash seems to be provoked while the start center initializes. Maybe it reads some "unvalid" data??


Most likely the crash occurs while trying to read one of your recently opened scores so it can show a preview. If you could determine which score causes the crash, and share that score with us, that would be very helpful. You might have to move or rename your scores in order to start MuseScore.

It seems something happen while musescore read Thumbnail. Something changed and last musescore crashes while read score. I believe it happen not with all of your score but with one of them. To utilize app you can run app with -F to prevent crash.
To find the bug please do the following steps. Try to open your last scores. If I am right musescore will crash again with one of score. If this happens upload score please.

I tried a couple of ways to remove "old" data:
- start with "-F"
- delete folder "MuseScore3Development" in document folder
- delete folder "MuseScore3Development" in AppData (Local and Roaming)
- rename my "normal" MuseScore folder (from version 2)

Nothing helps. After start-up I see the Start center for about 3 seconds while the mouse cursor displays activity (circle) and then it crashes with no comment.
I also tried to start from command line - in order to see any error messages. But the cmd-Window closes on starting "nightly.bat"...

Is there a flag that I can set manually in the configuration to suppress the start center?
In MuseScore 2 this was:


but it seems not to work for MuseScore 3 (or I don't know which is the correct section where to put it)

Interestingly enough, -n will start with the new score wizard, but then after the wizard finishes, the start center will appear. This cannot be desired behavior.

The tip to start with a score as argument was the "solution". Now I could disable the start center and go further with testing...

"I believe it happen not with all of your score but with one of them."

Which one (s)? Please attach this one, or one of them.
And with precise/detailed steps?

cadiz1, I think you misunderstand. From what we've learned, there seems to be something about Bacchushlg's system that is causing MuseScore to crash when WebView is enabled. The problem does not seem to be with any of the recently opened scores, as we had originally thought. This seems to be a good place to start looking for suspicious code, but without being able to reproduce the crash, and without further information, it may be difficult to diagnose.

Does disabling WebView really make all the difference? Both "Cheek to Cheek" and "Autumn Leaves" would trigger a crash if Start Center tries to show a preview for either score, regardless of whether or not WebView was enabled. Of course, it is possible that this crash is unrelated to either of those scores....

the option "-w" helped me. So the reason seems to be the Webview.
Also, the default directory for V3 is different from V2, so it should not "see" the damaged files.

V3 does not look into V2 prefs. Not does any development build look into any installed version's prefs. So no, recent files should not be shown after -F

I had a similar problem, that I reported as Issue #276060.
Unfortunately the probmlem dissapperared after running with -F, so now I can't trace it any more.

Bacchushlg I built debug version of MuseScore for you. In debug version there is a debug console which is used for some debug information. See the link bellow and download archive please. I'm not sure but may be some useful debug information will get into debug console. It may help to diagnose the crash. If this will not help I'll prepare specific musescore version with some additional logging output

In reply to by Bacchushlg


just came across this report while trying out the latest builds. Reason for me for testing is that I read somewhere that it is now possible to assign MIDI channels to the score manually.

I am having the same problem as the original poster: The start screen shows up (displaying a crash cymbal) and after a few seconds it dies without any notice. Trying -F, -w etc. all do not help, there is also no score that it is attemtping to load (unless it looks in the previous v2.3 settings).

I downloaded and tried the debug archive you have posted via dropbox and run that on my system, same result. However, I captured the debug output (attached to this post).

BTW, my system is Windows 10 latest build and patches, german language. If you need more specific information or would like me to run specific tests on my system please let me know.


Attachment Size
err.txt 36.74 KB

You seem to have a different problem. You should open a new issue called "MuseScore crashes when displaying splash screen" Please report you operating system and build number you are using in the report. Can you try to download different builds until you find one that works? Include any successful in your issue report also. It will help track down where the problem is.

I have come across this problem again.
(Running from my local build, so it may not be exactly same problem)

The console writes the message:

[20704:22608:1008/] Error reading broker pipe: Pipen er blevet afsluttet. (0x6D)
Danish text translates to: Pipe has been terminated.

I can locate the source of the crash to be somewhere in ScoreBrowser.cpp/setScores.

I can probably get the exact score if I can get hold of the filename - held in QString st = fi.filePath();
How can I output that in a qDebug?

Further investigation has located the crash:

Code snippet from void ScoreBrowser::setScores(QFileInfoList& s) in ScoreBrowser.cpp

 if (st.endsWith(".mscz") || st.endsWith(".mscx")) {
                    if (!sl) {                                      qDebug("D1");
                          if (_showCustomCategory) {
                                QLabel* label = new QLabel(tr("Custom Templates"));
                                QFont f = label->font();
                          sl = createScoreList();     <___
                    sl->addItem(genScoreItem(fi, sl));   //------Crashes here

If I open Ms restoring the pervious session and so by-passing Startcenter I am able to open the score that causes the crash.
Score is attached.

Crash happens both in my local build and in c77e761.

Severity S2 - Critical S1 - Blocker
Priority P2 - Medium
Regression No
Reproducibility Randomly
Workaround No

"Randomly" is because the issues is reproduced not for everyone.

Thank you very much handrok. Your application wax very helpfull to explain why my MuseScore application was crashing immediatly when started.

It was because it tried to initialize an ASIO device but this device was turned off.

As soon as I turned this ASIO device on, MuseScore stopped crashing when started.

Workaround No Yes

Workaround is to either use -w, or start MuseScore by double-clicking a score and then in Edit > Preferences > General switch off Startcenter

Can replicate reliably in 3.5.0 with Edit > Preferences > General > Startcenter ON
Workaround = start Musecore by opening an existing score then turn startcenter OFF

Fix version 3.5.1  

Indeed the workaround is to either use -w, or start MuseScore by double-clicking a score and then in Edit > Preferences > General switch off Startcenter
Note that depending on your screen size you may need to find the OK button at the bottom of that dialog, which might be off-screen. Simply pressing "Return/Enter" should do this for you, while that close button on the upper right won't!

Another workaround seems to be to check for and kill (using Task Manager on Windows) QtWebEngineProcess, and reinstall resp. repair installation (yes, this seems to be one of the rare cases where this might actually help)
See also #311727: Can't save a score online, brings up empty dialog and #310942: Freezes when clicking "Copyright and download settings" in Save Online dialogue. A reboot in between might help too

I was able to reproduce the situation described by Jm6stringer here:
I uninstalled MuseScore 3, after enabling StartCenter (so that "open StartCenter at startup" was written in the preferences) and installed 3.5.1. I then closed and reopened MuseScore a couple of times. And I also reproduced the bug #310942: Freezes when clicking "Copyright and download settings" in Save Online dialogue, closed the frozen window and then reopened the StartCenter. I then launched the updater via Help -> Check for Update menu. The installation went as described by Jm6stringer. After rebooting the system, MuseScore was crashing each time I was trying to launch it, except when using "-w".
In a Dbgview window the following was printed:

[7364] Qt WebEngine ICU data not found at C:/Program Files/MuseScore 3/bin/webengineresources/resources. Trying parent directory...
[7364] Qt WebEngine ICU data not found at C:/Program Files/MuseScore 3/bin/webengineresources. Trying application directory...
[7364] Qt WebEngine ICU data not found at C:/Program Files/MuseScore 3/bin. Trying fallback directory... The application MAY NOT work.

Indeed, C:\Program Files\MuseScore 3\bin\webengineresources\resources folder was empty.
I printed a list of all the files inside MuseScore 3 folder, reinstalled MuseScore 3.5.2 (which now was working properly) and compared the names of the files in the folder. In the faulty installation these files were missing:

C:\Program Files\MuseScore 3\bin\webengineresources\resources\icudtl.dat
C:\Program Files\MuseScore 3\bin\webengineresources\resources\qtwebengine_devtools_resources.pak
C:\Program Files\MuseScore 3\bin\webengineresources\resources\qtwebengine_resources.pak
C:\Program Files\MuseScore 3\bin\webengineresources\resources\qtwebengine_resources_100p.pak
C:\Program Files\MuseScore 3\bin\webengineresources\resources\qtwebengine_resources_200p.pak
C:\Program Files\MuseScore 3\bin\webengineresources\translations\qtwebengine_locales\en-US.pak
C:\Program Files\MuseScore 3\tours\autoplace.tour
C:\Program Files\MuseScore 3\tours\inspector.tour
C:\Program Files\MuseScore 3\tours\mmrest.tour
C:\Program Files\MuseScore 3\tours\navigate.tour
C:\Program Files\MuseScore 3\tours\noteinput.tour
C:\Program Files\MuseScore 3\tours\palette.tour
C:\Program Files\MuseScore 3\tours\select.tour
C:\Program Files\MuseScore 3\tours\spanner-drop-apply.tour
C:\Program Files\MuseScore 3\tours\timeline.tour
C:\Program Files\MuseScore 3\tours\welcome.tour

Additional Note:
When I launch MuseScore with StartCenter on, after I close it an orphan QtWebEngineProcess.exe process is left in the task manager. So if I launch and close MuseScore 3 times, 3 QtWebEngineProcess.exe are shown in the task manager.

Hmm, the missing webengine parts were almost expected (at least suspected that this part of the install went south), but why also the tours?

Would a (backup) copy of that icudtl.dat in MuseScore's bin direcory have helped with those crashes?

(and why don't we bundle all the other qtwebengine_locales\*.pak files)

icudtl.dat is 9.66 MB, I would avoid a duplicate.
Note that all the other translation files in qtwebengine_locales were present except for en-US.pak (which was probably in use by QtWebEngineProcess when the installer was launched).

The thing that strikes me most is that a QtWebEngineProcess.exe is left orphaned in the task manager list each time MuseScore (with Startcenter at startup) is launched and closed.

If both icudtl.dat and qtwebengine_resources.pak are present in "bin" directory, even if they are not present in bin\webengineresources\resources, then there is no crash.

Did you try the other workarounds, like opening MuseScore by double-clicking a score and then disabling start center? Or trying the Repair option from Windows? It's true uninstall / reinstall would also fix it, but that's the most drastic of these.

Ok so a lot of these things seem to involve commands, I have never used the command prompt in my life but would REALLY like to be able to continue arranging hymns so yeah i need some help.

In reply to by Jojo-Schmitz

Workaround Yes No

starting from the command line with the -w option did not solve
Note that I responded NO to the dialog asking to rebuild the previous session
I also reinstalled everything from scratch, so there should be no previous session
I tried to send you the DUMP but you servers denies (bad gateway error)

Regression No Yes
Reproducibility Randomly Always
Severity S1 - Blocker S3 - Major
Reported version 3.0 3.6

I don't know what half of this stuff means, I just wanna write music and after the new update (which I had to get because my old version wouldn't open unless I clicked for an update) the software won't stay open for more than 5 seconds. I've read the workaround above but I don't get what -w is or anything else that's already been written so please, please explain it in guy-who-dropped-computer-science-in-high-school-and-only-uses-this-laptop-for-gaming-and-writing terms.

The original bug discussed here is actually unrelated, it's from two years ago. What you are seeing is probably the result of a botched update that was not able to install one file that was in use by another program.

Solution is to reboot and then either uninstall & reinstall, or use the "repair" option in your installer.

I am not able to open the Musescore at all. As soon as I click yes to Restore the last file it goes into a crash. the program is useless

This problem has reappeared for me in the most recent update. The work around (open existing score and disable start centre) works for now but starting start centre will always crash.

For the record, Documents/MuseScore3/Scores is the default location for saves, so if you didn't choose a different folder when you first saved something, that is where your scores are. If you did choose a different folder, then they will be in that folder instead.

Status active PR created

After some local testing this is an educated guess at fixing the root cause created by the windows installer:

I would need an officially signed installer package to be able to verify whether it does fix the simulated error condition.
Side note: As I don't experience the issue directly myself I used a workaround to force one of the known trigger conditions (launch QtWebEngineProcess manually so it is blocked during the update). It seems to have the same behavior, but we'll only know for sure once someone that is actually affected by it can test it out after initial verification tests shows this has a chance of fixing it.

My initial test with the 3.6.2 installer package indicate that this issue should indeed be handled correctly now. Fingers crossed that my test scenario matches the real world cases out there for those that were affected..

Fix version