What is the actual cause of this stupid thing?

[RLVG]

http://i.imgur.com/CSd2wPe.png

[Cryptonic]

Try clearing your browser cache and see if it persists.

Ctrl+F5 on PC

[RLVG]

Try clearing your browser cache and see if it persists.

Ctrl+F5 on PC

It's always solved by shutting down the current window on the browser, but it's still infuriating as it happens non-stop to that specific window.
The question I have however, is the cause of this problem.

[SuperJack]

Because the token expired.

[Sen]

Try with a different browser and see if the issue persists. Let's narrow down the cause.

[RLVG]

Try with a different browser and see if the issue persists. Let's narrow down the cause.

It has happened on Chrome and Internet Explorer.

[SuperJack]

Best person to ask is MikeVipe. Send him a PM.

[Sen]

Firefox: Tools > Advanced > Network > Clear Cache
IE: Something > Something > Delete temporary files.

[Sen]

Make sure to do that while logged out. Then log back and give it a try.