Studio5000 "ASP.NET is not enabled or installed."

hai, previously I was able to open studio5000 and code easily, but now I am getting 'Server Initialization Server did not load: "ASP.NET is not enabled or installed."'
Actually Asp.net is installed as well as enabled too.
PLEASE HELP ME TO RESOLVE THIS ISSUE.

Proper version installed?
What does Windows Event Log say about it? Open the event log, look at both Application and System for Red marked events. See if any refer to ASPnet and resolve them.

Uninstall/Reinstall it. Could be corrupt or have a service that is faulting.

It has to be related to that useless start up page. Open the registry editor:

HKEY_Current_User\Software\Rockwell Software\RSLogix 5000\Start Page

Set Never Show to 1