Directory entries not showing 2nd page

I have been trying to add Active directory users to the clients list in order to manage their policies. 

I have around 840 entries in my AD. 

whenever I click on the arrow to go to the 2nd page it will stop showing anything. it will show the container only and it will be empty. 

it is strange because when i was using 7.6 i was working fine. 

now I am using 7.7.3 web security with windows server enterprise 2008 R2

I thought it might be the browser so i checked in major 3 browsers IE FF and Chrome all the same no 2nd page opening! 

I spent the past day figuring out a solution also i couldn't find anything about the issue only ! 

Thanks, 

Abbasi