Hello. I just had this same problem a few minutes ago and that solution also worked for me. But I am wondering, is this a server problem? Or a punBB problem? And would there be a way to hack punBB to know when this is happening? I had a user email me a few weeks ago with this same problem but it was during work so I didn't get the email until I got home at which point it had fixed itself and the user was back to posting again. But this time I was home when it happened. So it's even more annoying that it was a real problem and not a fluke.
BTW, the error started coming up after my host or server (Where the site is hosted) went down for a few minutes. Could that be related?
I just want to fix this as soon as possible. Because I can't tell how often this is gonna be happening.
Edit: By the way again, my server is off by 10 hours (Behind. It says 1:56PM now when it's really 11:56PM.) I'm Eastern. The server is Eastern and my timezone is set to -5 Hours (EST).