How can I profile prefab assemblies using VS 2012

This is basically the same as How can I profile the signature assembly using VS 2010 or VS 2013 , but after running

sn -Vr *

      

        
        
        
      

    

successfully (in zoomed cmd.exe) as suggested with the most votes .

I still get this dialog for every strong dll name selected for instrumentation

x.dll is signed and instrumented, this will invalidate its signature. If you continue without an event after the tool to re-sign the binary, it may not load correctly.

and it doesn't matter if I click yes or no, VS won't profile. So how can I get the device profile?