Well the log file explicitly states the problem. It cannot find the files.
Linux is case sensitive, and for as far as I know, the /home/ dir is always lowercase. So there is no way it will be able to find the music.
Also, the dir says /home/shared/music
Shared, possibly from an external drive? Possibly this drive was removed or remounted with a different name?
Indeed, the db did not get recreated. Try shutting down firefly, removing the db, and restarting firefly. That should do the trick.
(Could take a while on restart, as firefly does a scan before running web adminpage)