Just now MusicBee completely froze on me. There is no '.. is not responding' message which is odd. It happened after a song stopped and I double clicked another one to play, nothing happened at all.
It was like that for 5 minutes or more. Then I selected Close Window from the taskbar, still no response after several minutes. The taskmanager tells me MB is using around 0,1 % CPU. I killed the task from there, that worked immediately.
Then, upon restart I got an error. The file cache is corrupted and could not be loaded. The last backup has been recovered, et cetera.
Do you need the error log?