Help tracking down rare case of corruption on save

• Apr 3, 2023 - 12:58

Saved files become corrupted on opening. "Open anyway" doesn't work. All the files are saved and closed during the previous session without any message like "File cannot be saved properly" or "Can't save the file", however, when you open them on the next day, they are corrupt and unopenable. Here is one file that became corrupt and I am afraid is lost for good:
EDIT [of 2023.04.05]: As the discussion here and on GitHub (here: has shown, files most likely get corrupted on save, not on opening.


A MuseScore mscz file is a zipped directory with some files, one of which is an mscx file that mainly contains the score.
In your file, this mscx cannot be extracted due to a header error. If you open it with MuseScore, the program needs to extract also the content. It seems to happen again and again with MuS 4.
You should for serious work either take MuS 3.x for the time being or at least save it frequently under always new names (cuba_11_of_10_V1.mscz, cuba_11_of_10_V2.mscz etc.) to have at least an older version.
The attached file is unrepairable in my opinion. Search for a backup / autosave file on your computer.

In reply to by innerthought

It depends on your computer operating system.
In Windows there is a hidden folder called .mscbackup but you only can see this folder if you had made them visible in an explorer window ("extras / folder options / view" and there you should uncheck "don't show hidden files, folders and drives", may be a different wording because I use a German Windows version).

And a comment by Jm6stringer from an other thread:
Try looking in
for any mscz files with (strange) alphanumeric names beginning with "sc".
One of them might be a usable backup.

In reply to by HildeK

Can you point to other posts about header issues in MU4? I don't recall seeing any. Tons of reports of zero-ed out files in MU3, of course. I suspect any such problems are the result of the libraries MuseScore uses to write ZIP files, but so far, no one has found precise steps to reproduce the problem.

Anyhow, I can confirm that this file is corrupted in that way. It's not the same file as attached to the issue, though - that file opens just fine.

In reply to by Marc Sabatella

Marc, you said (here:…):

"The issue has not been fixed because you haven't yet given the steps to reproduce the issue"

-- But I don't know what other steps I can possibly provide except for these:

1) you create a file;
2) you wrok on it;
3) you save it without any problems;
4) then you try to open it only to see that it is corrupt;

I doesn't happen all the time, but from time to time, which is even worse.
I really don't know what kind of higher precision of the steps described above I could provide.

In reply to by innerthought

Since it doens't happen all the time, what you need to do is try to start being aware of what is going on differently the times when it happens versus when it doesn't. Eg, did the computer crash while working on it? Were you using an external drive? Were you running an external sync service? Was it while also running another audio program? Something must be the variable that is the trigger here. Once enough people decide they want to help try to track this down and start pooling their collective experience to look for common patterns, then hopefully someone will be able to figure it out. So it's up to the people to whom this has happened - which, despite thousands upon thousands of saved scores over the past 12 years, does not include me - to try to work together to brainstorm about what is going on the times when it fails that is different from the times when it doesn't.

So your first step is to start being diligent, and the next time it happens, return here and try to describe anything even slightly unusual that you think might be a factor, so others can try it out and experiment and discuss further.

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