I know this is a simple problem, but I am tired of spending time on it. I have Visual Studio 2019 and Intel Parallel Studion XE 2020 Composer Edition for Fortran Windows. I have a large mixed language project C++/Fortran that compiles into a dll, abbvsc.dll. That works fine. The dll in turn is used by an electric utility loadflow/dynamics program. That program is psse.exe, although the name is beside the point. I cannot get Visual Studio set up so I can debug the dll. No matter what I try I get messages like "target is not set" or "abbvsc.dll is not an executable" or other unhelpful messages. Can anybody give me a hint on how toset this up. I had it working before Christmas but no joy now. If I remember correctly the debugger starts psse and then when the appropriate command is entered into psse a breakpoint is hit in the dll and things stop. From there you can single step. Any help appreciated.