MuseScore 3.4.2 does not open mscz file written by version 1.2
I want to open one of my older MuseScore 1.2 files with MuseScore 3.4.2, and it fails, telling that the file is corrupted.
Details (in German): "Takt 6, Notenzeile 1 unvollständig. Erwartet: 4/4; Gefunden: 72/48"
Translation: "measure 6, line 1 incomplete. Expected: 4/4, Found: 72/48"
I have created many files using MuseScore 1.2, most other files apprear to have similar problems.
MuseScore 2.0.0 (on my retired PC) could open these file without problems.
What options do I have to reuse the files with version 3 (without downgrading to version 2)?