Write Error picoreplayer mount cache LMS favourites

Hi there and sorry, if this question has already been answered but I couldn't find a solution. I am a total Linux noob!

My setting:

• DS 118 with DSM 7.0-41890
• piCorePlayer v7.0.1 on a PI connected to DS via cable

For creating mountpoints I did the following:

• On the DS I activated NFS Version 3 with no further settings
• Also on the DS I chose the shared folder "music" and editetd the NFS-permissions
  
• in the LMS settings of the picoreplayer I added a mountpoint as follows
  
  I had to leave the option section blank, because by specifying the uid 1001 and gig 50 I received an error when trying to mount

So far so good.

No I wanted to move the cahe of LMS to the NAS (I SHOULD do that, shouldn't I?). However, I did as described above to create a mountpoint with a new shared folder. After done that I assigned the new mountpoint to the setting "Save LMS Server Cache and Preferences to Mounted Drive". Everything seems to work fine.

But when I try to save favourites I get an error "Fehler beim Speichern der Datei /usr/local/slimserver/prefs/favorites.opml". Additonal I can't update Plugins. So I guess I have a rights-problem, because moving back the LMS Cache to the defalt (SD on the PI) results in havein no problems anymore.

Can someone give me a hint what to do, or is moving the cache to the nas not really usefull?

Thank you very much!

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