Admin internal pages blank out

[redline]

Hi, I dont know why my second level admin pages blank out out of a sudden.

I have cloaked my admin page. Admin login page is fine and I can see the admin default page but when I click on any internal pages, there's only a blank screen.

Thanks.

[stepsdesigns]

what is the url of the blank screen ?
and did u change any of your site configurations

[redline]

I changed the Login Session Lifetime: to 999999999
It works now after changing to 99999

Why does this happen?