Error=XML_ERROR_EMPTY_DOCUMENT ErrorID=13 (0xd) Line number=0

Does this one work? It may contain your notes but lose some style and other attributes.

From the console in ubuntu I ran:
zip -FF (filename) --output (newfileneame)

Then I extracted the mscx file that the archive contains.

0 bytes, no hope :(

The ZIP arching (which an mscz file is under the covers) is broken

The extracted mscx file works without an error in MuS 3.6.2. (Open the mscz using a zip tool and extract the mscx).

You can open a score in MuS 3.x if you extract the mscx file from the mscz file with a zip tool and open this mscx file. However, the text formatting of the title block is usually lost in the process.
If this does not work, which happens sometimes, there is a major bug in the file (only zeros; corruption during the zipping process etc.).
.If you have scores written in MuS 3.x, it makes sense to copy scores into the MuS 4 score folder and not to overwrite the 3.x originals with version 4.

Otherwise: also here the suggestion to reset MuS 4 first to factory settings. Maybe that is enough to be able to open the file again.

Attached is the file saved with MuS 3.6.2. You should also be able to open it with MuS 4.

The usual trick: extract the mscx from the mscz...

Actually not even needed: that mscz just opens fine in 4.0.2 here

Desafortunadamente, la parte de este archivo que contiene la música está demasiado dañada para poder repararla.

Sadly, part of this file is missing and the music data cannot be read.

I'm affraid it is a broken ZIP archive

I extracted the mscx (as described above) and opened your score in version 3.6.2. I found no errors.

Have a look on the file size: 0 bytes = no content.
Search for a backup copy, e.g. in the hidden folder .mscbackup.

> Could someone give instructions on how to fix the problem in the future?

This error message comes for a number of different problems, so there is no standard answer for it. However, it is very often related to the zip process when saving.

If you've looked at the other posts here, you know that you can open the mscz file with a zip tool. Often you can extract the included mscx file with the full score and continue working with that. Unfortunately not here, it's corrupted and can't be extracted. First try to find an older version in the hidden folder .mscbackup. If that doesn't work, I still see the possibility to recreate the score from the fortunately existing excerpts:

• Open the file with a zip tool (7-zip, Winzip, etc).
• save the folder 'Excerpts' on your PC
• create a new, empty score with all instruments
• open the mscx files of the excerpts one after the other and copy the notes into the new score.

This is not little work, but much less than rewriting everything.

I also recommend that when you write a score, you regularly make a copy under a new name so that if something goes wrong, you don't lose everything.

Try this, opened in MuS 3.6.2.
Title formatings may be have lost.

Cannot be repaiered. This file contains only about 37k bytes zeros.
Search for a backup copy, e.g. in the hidden folder .mscbackup

I was able to extract the .mscx file which opened OK and saved in MuseScore 4.
Here it is:
Mayr araqsi aperov4.mscz

It's not necessarily a panacea, but have you tried opening your file with 4.1. Release Candidate ? https://musescore.org/en/node/352060
If it doesn't open, please attach your file for help. There is another way : https://musescore.org/en/node/352137#comment-1197851

Unfortunately, this file has 0 byte file length, i.e. absolutely no content. I am sorry, it cannot be repaired.

There is a hidden folder in your score folder called ".mscbackup". You may find a backup copy there.
Ask on the Internet how to make hidden files and folders visible in your operating system (which I do not know).

After zip repack opens fine in Musescore 4.1.1

It's full of zeros. You can check this using a hex editor program - I used Bless in ubuntu, others exist.

Unfortunately, it cannot be restored.
Same problem as with some other files in this thread: The file contains only zeros.

Fixed

The file is full of zeros. As mentioned above, you can check this using a hex editor program - I used Bless in ubuntu, others exist.

Folders where you can search for musescore files (Windows) if you did not save one:

• C:\Users\{YourUserAccount}\AppData\Local\MuseScore\MuseScore4
• C:\Users\{YourUserAccount}\AppData\Local\MuseScore\MuseScore4\cloud_scores
• C:\Users\{YourUserAccount}\AppData\Local\MuseScore\MuseScore4\cloud_scores\.mscbackup
• C:\Users\{YourUserAccount}\Documents\MuseScore4\Scores
• C:\Users\{YourUserAccount}\Documents\MuseScore4\Scores\.mscbackup
• C:\Users\{YourUserAccount}\Documents\MuseScore4\Cloud Scores

This list may be incomplete or incorrect though
If you find something interesting, copy that file to another location and open from that new location

Try this one.
I extracted your file with 7-zip. You should get it and learn how to use it. You never know what might happen. This time I got a auto save file that opens. Never seen that before.

This file is beyond repair.
Folders where you can search for backup musescore files (Windows):

• C:\Users\{YourUserAccount}\AppData\Local\MuseScore\MuseScore4
• C:\Users\{YourUserAccount}\AppData\Local\MuseScore\MuseScore4\cloud_scores
• C:\Users\{YourUserAccount}\AppData\Local\MuseScore\MuseScore4\cloud_scores\.mscbackup
• C:\Users\{YourUserAccount}\Documents\MuseScore4\Scores
• C:\Users\{YourUserAccount}\Documents\MuseScore4\Scores\.mscbackup
• C:\Users\{YourUserAccount}\Documents\MuseScore4\Cloud Scores

This list may be incomplete or incorrect though
If you find something interesting, copy that file to another location and open from that new location