Extension Methods not Recognized

Question

What is necessary to have an extension method honored when it exists in an imported assembly? I built one in a class library project but it is not recognized in my web proj

Answer 1

In my case it said the reason the method was not recognized had nothing to do with extension methods, but an error in the same file which did not show up in the IDE - For me the solution was restarting the IDE and it suddenly displayed the actual error i had to fix.