This website has been configured to disallow editing with SharePoint Designer

Issue Description : When i tried to open a site in sharepoint designer , it throws a below error.

Error message : "This website has been configured to disallow editing with SharePoint Designer"

Resolution:

1.Go to Central administration
2.Application Management à Manage WebApplication 
3.Select the web application having issue.
4.In the Ribbon, Click on General Setting à Sharepoint Designer Settings 
5.Check "Enable Sharepoint Designer" .

That's It . Now i am able to open the Site in designer.