Custom NPC Server error

[zB3nny_]

Hello, 

I've installed the Custom NPC Mod for 1.12.2 on my Server. I can create them, change the Skin,
make everything else without of changing Parts or Spawn clones.

I searched the internet for an solution, but i didn't find anything. I donk know what ive to do now.
If you need a File or sth. else i can send it. 

Best regards

zB3nny_