dunster

That was a copy/paste error.

I found out now, I made a new role for ai1ec_event_assistar with the same autorities.
Now it is working …. really strange
The ai1ec_event_assistar was automatically made by the events plugin.

Thanks jefecame

I have 3 blogs in one website, so I did checked these too.
Also the other blogs has the same problem.

So I called my hosting company and they found out that MySql had troubles to write temporally files in a specific directory.
They created the directories again after deleting.
Now everything is okay again.

I have exactly just now the same problem as you describe.
I have WordPress 3.1.2

So I wait a few hours and everything is fixed again ???
Hmm