I had Sub-Zero 1.3.33.522 working fine. Then I bought a Synology NAS. I soon learned that as great as a NAS is, it has its issues.
I had an error with Sub-Zero. As soon as I opened the Sub-Zero channel every library showed "Insufficient Permissions" See the screenshot attached.
My whole Plez set of library folders were in a typical "Shared Folder" structure. To fix this I just went to the NAS control panel and created a user named as my Plex admin and gave it the same password. I then gave this new user permission to read and write to my the whole Plex shared set of folders. Fixed! Well....
Everything worked but I did not enjoy the instant updates when I dropped new movies into my libraries as you do with a direct connected drive. I learned also a NAS is NOT the same a direct connected drive in that it does not inform the OS of file changes immediately as a direct connected drive does. In Plex this meant the "Update my library automatically" stopped working. I have to use the "Update my library periodically" instead. I did not like that.
So I learned about iSCSI connections. That makes a NAS react more like a direct connected drive because amoung other thing it is a dedicated connection to just one computer and the OS treats it as a typical internal drive once all is set up.
Now I had PMS watching folders like a directly connected drive and all works now EXCEPT I get the error for each library "Insufficient Permissions" again AND I can not control users and permissions from the NAS control panel anymore because the OS is in control now.
I have tried a few things. From the computer connecting via iSCSI I created a "File sharing user" and I gave the whole drive permission to read & write to the user named the same as my Plex admin with the same password. didn't work. I tried selecting "Ignore ownership on this volume". Didn't work.