Ok this bug has been reported over and over and Anet has not fixed it.
Which makes me think that it is not a bug, that it is intentional, that some anti bot code is flagging humans incorrectly and disabling us.
Because you can move around, you can chat you can do this or that. But you can not attack, you just stand there and die or run away whatever. If you zone it resets, if you relog it resets.
Because it has been around since Halloween and before.. Anet is on the ball for fixing things. So either it is not a priority or it is intentional. And I can’t see such a bug sticking around for so long.
I am really tired of this bug, it is always at the worst time, in the middle of a group event or a dungeon.
So in conclusion, please fix your anti bot code because you are picking on players who simply play.