I have two sites, both running xenforo. I didn't have the foresight to set them up to use the same username/passwords. Is there a way to combine them now? Bottom line: Each site has 2,000+ registered users, and many visit both sites. I'd like it set up so a user only needs to be registered and signed in to one of the sites, and can seemlessly go to the other site. I guess my biggest concern is if there are any duplicate usernames. Any thoughts? (If this is the wrong forum, please move, and accept my apologies.