I had this and it was to do with timer settings on my laptop - clock was not quite synced with theirs. Other people have said they have had cookie related issues. TBH I find these pages more helpful these days, and populated with people who are more inclined to help!
Anyone else get this? I'm new to using TES but registered a while ago. I log in, then whenever I try to get onto the community pages, I have to log in again. Then again. It never lets me actually post anything.