Thread Prefix Set not working
 

I create a Thread Prefix Set, and it appears to create it, but its really not fully created.

So it appears there, and I try to add a Prefix to it, and the drop open NAV where you choose where you choose what Prefix to add to what set, is empty.

Example I create a Prefix Set called Crimes Committed and given it the ID of c_c

Then when I go to add a prefix to the Set, nothing is there where the Set should be in the drop open.

Then when I delete the phantom non-existent Prefix set it says: Are you sure you want to delete the prefix set called ''?
(prefixsetid: c_c)

I have disabled the few mods and tried many times, yet no real Thread Prefix Set is created.

Can anyone assist?