Holly Fralto

I'm on macbook .. never had problems with the updates before

Every time I try logging into SL a message pops up and says "Login failed. DNS could not resolve the host name. Please verify that you cant connect to the www.secondlife.com web site. If you can, but continue to receive this error please go to the support section and report this problem." I have uninstalled & reinstalled SL three times. I've tried two different viewers. Anyone know what I can do?