I had this same issue. I completely uninstalled NFAU and reinstalled.
I also removed the "objects" that were supposed to have been created.
In NW6 there was supposed to be an NFAUUser object, but I sure
couldn't find one. My server was patched to NW6SP2, but after
removing NFAU and reinstalling, it is unpatched.

I still have some other issues, but you might want to try this.