In some cases when I try to set “Start external programm” on tab “Debug” in settings of C# project and press F5 I see an error “debugger’s protocol incompatible with the debuggee”. In what cases it can occur?
If code of dll is in vs2008 project and application code is in vs2010 project can I debug library running application through “Start external programm” option?
The managed debugger interface was changed in .NET version 4. You cannot debug a .NET 4 program with the VS2008 debugger.
Use the VS2010 debugger instead. Setting breakpoints in a DLL that you built targeting an earlier .NET version isn’t otherwise a problem.