You have more than one static method named "Main". Search in your code for static methods named "Main", and remove or rename the extra.
The Main method is the entry point of a C# console application or windows application. (Libraries and services do not require a Main method as an entry point.). When the application is started, the Main method is the first method that is invoked.
http://msdn.microsoft.com/en-us/library/acy3edy3(v=vs.110).aspx[
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