Getting Error Message when adding Content pages with Master Pages in ASP.Net

Hi Friends,
 
I was able to create Master pages and content pages.
 
Not sure what happen all of a suddend, now unable to add content pages though I opened Visual Studio 'run as Administrator'
 

I tried with both Web application and Web site.
 
Here I dint find an option to attach my error message with screen shot.
 
Kindly look at the error message and please help me.
 
Web Application Error message is : The template file used to generate the content page cannot be found.
 
Web site Error Message is : The content page cannot be created because the language specified for the master
page, 'C#', is not supported.
 

Regards
Reddy