Bad performance of MuseScore

MuseScore 3 stopped working properly after the last update. After switching on, it switches itself off within one second. It can only be attached by running any file in .mszcz format. Moreover, the import from all types of files, for example xmml, has been blocked. Only the import of files such as PDF is left.
Less and less sheet music to download, most have become paid.
In a word, it gets worse. Time to say goodbye.