An Error Has Occurred!

[inchina]

Hi,

An Error Has Occurred!
The last posting from your IP was less than 360 seconds ago. Please try again later.  

This error appears quite often when I logged in and want to reply to a private message. I did not send any messages before (after login).
Win 8.1 IE11 all updated.

Any hints how to avoid this?

Regards,

inchina

PS Same error with firefox

[inchina]

Thank you!
I spent some time reading some posts and I found it by myself 
Some kind of RTFM