As soon as I start the game up I get this error message: http://imgur.com/dOEAtF9

And after that a few different things have happened:

The first time, the server browser worked fine but as soon as I tried logging into a server the game crashed with the memory error that it usually gives when you close it down.

The second time I tried, the server browser would not respond at all, the entire client was frozen.

The third time the server browser was incredibly unresponsive, but by patiently waiting about a minute for each click to register I was able to enter a server, but my framerate was stuck at 4 and I got "No message received" within a few seconds.