Yesterday, there were reports on my friend's xenforo about this error. My friend attributed it to either the host or xenforo going through some cron jobs. Of course, the error is gone now. I'm researching what might be reasons why someone might get this error. ===== Important threads on this Topic ===== http://xenforo.com/community/thread...-error-occurred-please-try-again-later.29591/ - in that thread Floris has some good suggestions which applies to this situation. Research continues. The Debug mode + error logs is a good idea.