hmm actually i'm still getting the problem with jriver just closing for no reason sometimes. It generally works ok but on the odd day i'll try to connect and as jriver has unexpected close i can't access through gizmo or panel unless i go to the pi and start up jriver again. anyone else experience something similar? I am definitely only using for music now. (after thought.... although the films are still in the library im just not playing them via the pi any more, thinking i should probably in the first instance remove those folders from the library will try that tonight, also could try reinstalling j river)
I used to have that occasionally, and I setup a systemd service to auto-restart (stickied at the top of the MC24 forum, but not in the MC25 forum for some reason).
A.D.'s right though, if you have auto-import enabled, I'd bet on a bad file crashing things. Also make sure the thumbnailing priority is set to low.
If it's a client system rather than a server system, try turning off "auto-sync with server" just to test, as I sometimes see a memory leak with that setting that eventually crashes MC.