Me and a friend were talking in pms, when suddenly when I tried to reply to them it gave me an Error 403 Forbidden message. I can respond to all other pms, but not this one person. A screenshot of the error:

It reads: Forbidden; You don't have permission to access this resource. Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

yea that happens sometimes, just click back or reload