library scan doesn't work anymore

server-freebsd

#1

when I hit the "scan library" (any library I have) then I see a short reaction, but then nothing more
and when I look I see no scan running as the text in the drop-down list is "scan library" and not "stop the scan"!
so no scan is running
Plex server version = 1.12.0.4829


#2

see https://forums.plex.tv/discussion/289608/library-scan-not-working#latest