Indeed.
The MuseScore mscz files are zipped files that can be opened with a zip tool. But my 7-zip reports a header error when I try to unzip the included score. So in my opinion it's corrupted, but there are other zip tools that might be more successful. To test, you can rename the 'mscz' extension to 'zip', maybe your zip tool can then open it and successfully extract the mscx file.
In the meantime, look for a backup file located in the hidden .mscbackup folder, right in the folder where your score is stored.
Ask a search engine how to make hidden files and folders visible to your operating system.
Comments
Indeed.
The MuseScore mscz files are zipped files that can be opened with a zip tool. But my 7-zip reports a header error when I try to unzip the included score. So in my opinion it's corrupted, but there are other zip tools that might be more successful. To test, you can rename the 'mscz' extension to 'zip', maybe your zip tool can then open it and successfully extract the mscx file.
In the meantime, look for a backup file located in the hidden .mscbackup folder, right in the folder where your score is stored.
Ask a search engine how to make hidden files and folders visible to your operating system.
Seems to be a corrupted ZIP archive