Using VS 2013 and .net 4.5.1 but still getting “Changes to 64-bit applications are not allowed”

Question

I'm using VS 2013 Ultimate with Update 2 on Win 8.1 x64 and VS won't let me use edit and continue on a simple console application. The console app is set to use .net 4.5.1 and AnyCPU but whenever I try to change code while debugging I get the dreaded "changes to 64-bit applications are not allowed" message box.

I've tried making sure Edit and Continue is enabled in Tools->Options. I've tried flipping it off and on again...no good. I've tried disabling all my VS extensions...didn't make a difference. I've tried resetting to the default VS settings...nope. I've tried repairing my VS installation...nothing. I've tried verifying my .net framework installation...it says my installation is verified but I still have the same problem.

Anyone else seen this?

Answer 1

My crystal ball says that your debugger is using an older debugging engine. Another side effect is that you would have never seen the new method return value debugging feature.

Tools + Options, Debugging, General, untick the "Use Managed Compatibility Mode" option. This option is actually only required to revive C++/CLI debugging.