It is probably the Gloss causing the problem, try running the Gloss as Heavyweight 2, if it works (doesn't fault), then the finisher won't fold coated/gloss stock.
Booklet with cover and text
Product Name: Xerox Versant 3100 EX 3100 Print Server Powered by Fiery
Operating System: Windows 10
I'm trying to print a booklet with gloss cover and offset text and finish on the Plokmatic finisher. I get an error saying "Finishing (DFA Finisher) not supported by selected media (Plain Coated). It will print and finish if I print all on the text, but not if I choose a different stock for the cover.