Administrator Login = results in blank page

hi

I am in a bit of a dilemma… i have a OJS 2.4.x installation running and suddenly today. I logged in and found a blank page. The website is working , front end is working, i can log in with my username and password but i cant do anything after login…

Please help me what i can do to trouble shoot the issue. I cant even find out the exact version of my OJS install … I need urgent help…

Regards
ATIF