Microsoft Visual Studio 2012 cannot set breakpoint in c# file

Question

I have Microsoft Visual Studio Professional 2012 installed, version 11.0.60610.01 Update 3.

When debugging a c# (.cs) file Visual Studio gives me the following message

Answer 1

If there is no instructions to execute on a line, VS refuses to set a breakpoint an offers no reason. EG

string str; //Cannot set breakpoint
string str = ""; //Can set breakpoint