You may have a conflict with another workshop mod on the server. on a windows server you can do a string search in the workshop mods to see if there's other mods with the same id. using the command findstr /n /i /S /c:"ID 52551" *.dat in the folder <server dir>\Servers\<server instance name>\Workshop\Steam\content\304930. You should only get 3 lines back under workshop id 633172336(this workshop id.), if there's no conflict.

Thanks