Saving in MuseScore 4 makes .mscz documents unreadable by MuseScore 3
Although MS4 and MS3 use the same file format extension, .mscz, the file formats used are obviously not the same, since an MS3 .mscz file opened and then saved in MS4 will no longer be possible to open again in MS3.
This is very bad practice! If the file formats are different, then they should be represented by different extensions – that way, in addition, the original MS3 file will not be erased when saving in MS4 format.
Also, there is no warning from MS4 that a file will not be readable by MS3 anymore. I very nearly lost one file, on which I had spent a lot of work, that way (luckily I had saved a transposed version and could retrieve the file that way).
Bottom line: give the MS4 files another extension and all will be well. Right now all is NOT well.
Kommentit
There is a warning when you overwite a score. If you ignore that, you'll indeed loose the 3.x version, else you won't.
The behavoir you're seeing and complaining about is the same as it was between MuseScore 1.x and 2.x, and between 2.x and 3.x.
It is unlikely to change between 4.x and 5.x...
In reply to The behavoir you're seeing… by Jojo-Schmitz
There is a warning from the system that I am about to overwrite a file. It doesn't say it will be lost to earlier versions. Regardless of how often this has been done before, it's lousy practice. Imagine Word overwriting .doc files with .docx format.
In reply to There is a warning from the… by dbaeckstrom
It does overwrite doc files with newer version of the doc file format though
In reply to There is a warning from the… by dbaeckstrom
It also tells you on first open that you're importing it from a previous version (and which).
In reply to The behavoir you're seeing… by Jojo-Schmitz
Yes and lot of users including expert IT people like me have already described that as bad practice.
V3 was a different format from V2 and should definitively have a different extension, like now V4 vs V3. But well Musescore dev team has decided otherwise so we can forget about it I'm afraid.
P.S. that is an answer to the first message about versions change.