New Media Source Won't Scan

[gnattu]

You need to run Jellyfin as the same user you mapped that network share. Like you Mapped the smb to X: with user John jellyfin also need to be run with user John, run it with admin will not work.

Also, network path will be removed and will stop working totally in 10.10. You'd better change how your libraries are managed or you are locked to 10.8 forever.