Client crashes immediately after loading screen

[Sorphonark]

Hello everybody,

everytime I log in to the game, my client always crashes almost immediately after the loading screen. There is a small window that appears for not even a second, but I managed to get a screenshot from it. It says:

"Your performance level has been changed to a recommended level based on your system hardware to increase stability"

Screenshot: http://imgur.com/5PPbtKJ

I already disabled the write-protection and turned off my firewall/anti-virus.

Thanks in advance for your help!