I get that come up from time to time ever since the forum changed to the new software. It comes up often for periods, spells when it just comes up occasionally and then a few weeks when it doesn't come up at all but just when I think it's a thing of the past it keeps appearing again!
Yup, happens to me a lot. What I do is just refresh the screen and problem solved.
There's was a setting on the homepage where you could adjust the refresh rate. Don't t know if it's still available, but have a look.