I am working on magento project and has some issue with it, I have searched a lot over the net but didn\'t found anything related with this.
1) under admin > catal
You need to do some basic debugging to answer this question. Enable the error log and check it for errors on the page, this will hopefully give you an error message if you don't have one already.Check system log
If you have any new modules, remove them temporarily.Try reverting to an older version of the code that works, and then see what changed between the two versions.
Try to increase PHP memory_limit and check once.