Enable “debug” (but not “verbose”!) logging on the server, then hope it retains enough log files so you can find something in there after the next occurence. (Look for the word “destroy”)
Also, if you want the server to behave more predictably, switch to the storing and organization principles laid out in here Refresh of library is not picking up changed file metadata - #2 by OttoKerner , instead of throwing all tracks into one unsorted folder.
