MuseScore doesn't start anymore, as there's another one still running in the background
I wanted to change the length of multiple half notes by selecting them and clicking on quarter note, so that all are set to this length. The notes were in multiple voices (1 and 2). It was an imported midi file for which the quarter notes were imported as half notes with staccato dots. The midi was imported into MuseScore in November of 2018 (one of the latest versions at the time), saved as project (mscz) and reloaded now with MS 3.6.2. When I clicked on the quarter note symbol with the notes selected, MuseScore crashed and now it doesn't start. Yesterday, exactly the same happened, but MS started again after rebooting the PC. Today, even after rebooting the computer MuseScore doesn't launch.
Trying to launch it from the terminal, I see the following output:
(base) luiz@luiz-Aspire-V3-772:[~/Downloads]: ./MuseScore-184.108.40.2068021370-x86_64.AppImage /usr/lib/x86_64-linux-gnu/libjack.so.0 /usr/lib/x86_64-linux-gnu/libnss3.so (base) luiz@luiz-Aspire-V3-772:[~/Downloads]:
After accessing the shared library
libnss3.so it immediately stops loading and it gets back to the input mode on the terminal.
OS: Ubuntu 20.04
Using Jack integrated with Pulse Audio and ALSA.