Hello, I also have a problem with the wrapper...!
I have installed the wrapper as explained in the first post. When I connect to my Synology NAS via UPNP all movies are played with Kodi's player. When I connect to the NAS with NFS none of the movies are played at all...

! So the wrapper appears not to work...
When I open the wrapper again, it says "playercorefactory.xml already exist"...so I assume that the wrapper is correctly installed...
UPDATE:
Found the solution:
1. Connection must be established via SMB.
2. Guest account must be active on the NAS.
Now works fine

!!
regards, wiwnet