White screen when going to menu or plugins

Hey, I have ClassiPress theme installed and everything was working great. Then I installed the google xml sitemap plugin and it crashed my site so i deleted it via FTP. I then tried another one and same. Then I tried Contact form 7 and crashed it as well. Deleted it. Now when I go to Menu or Plugins I get a white screen. Everything else seems to work fine. Also if I switch themes I can get to Menu and Plugins no prob.

Any suggestions on what when wrong and how I can fix it?

Thanks,

Zac