Can't use rsync and USB-Backup

Hey Guys, hope you can help me.

I tried to use the USB-Backup Plugin but after creating the Task when i need to apply the Pending configuration changes its gives me this Error: (.txt Attachement, wont let me upload due to too many Words)

Same error after trying it directly with rsync.

Whats the Problem here? I just want to Backup a Shared Folder so an external Device.

Thank you very much.

Edit: rsync gets a different errror.

Ok thank you. I removed one Drive of a ZFS Mirror due to a fault, The Pool is still Online and i can access the Data from the Pool. Shouldn't it be enough to have the Data on the remaining drive to back it up?

Edit. Deleted my last Response cause it didnt worked

How do i change the mountpoint a shared Folder is reffering to?

Cant edit the Shared Folder (Gives me an error).

Now i got it to work. The "Device" in the shared Foler Tab was missing. in the ZFS Section i hit "Discover" and they reappeared and now everything is working. TY for Helping me