II ran into this issue yesterday, my system became unresponsive after I did a search in the YTMusic plugin. After doing some other things (reboot, check SD cards for errors), I figured the first step was to remove the YTMusic plugin. In addition to issue the command;
rm -rf /data/plugins/music_service/ytmusic
I also removed the plugin from the config file:
sudo nano /data/configuration/plugins.json
and remove the part related to the ytmusic plugin
restart volumio;
volumio vrestart
System was functional again, and installed the 0.2.2. plugin. Problems solved.
ETA: I did search the volumio community, never figured the issue would be discussed in this topic. It would have been a lot faster to get this issue solved if a new thread had been started specifically for this issue 