Stewman

What do i need to do ? do i need to downgrade the older version ? I have a mac book

I need help its been more than 3 days now and what started the problem is when i was playing it kick me out and then i could not log in and i update the 2.6.3 and it keeps saying the log in faild DNS could not resolve the host name . What do i need to do pls help me . I have a Mac