Cannot connect to CRM Server!

Hi all,

Since yesterday it's working fine, don't understand why isn't it connecting now.
I try to connect localhost (http://localhost), same issue, am getting error.

An error has occurred.

Try this action again. If the problem continues, check the Microsoft Dynamics CRM Community for solutions or contact your organization's Microsoft Dynamics CRM Administrator. Finally, you can contact Microsoft Support.

Has anyone gone through this situation ?

Thanks in advance to share any ideas
Chowdary