How do you run the program?
I need to copy the compiled BasicPlugin.api under Acrobat\plug_ins folder. I can create a subfolder of plug_ins and copy the .api file there. Just one level deep: if I create a subfolder under a subfolder of plug_ins, the .api file will not be found by Acrobat.
Then I need to restart Acrobat and I find the plugin running. In particular, BasicPlugin add a new Acrobat SDK menu and a menu item under it.
If I close Acrobat and go back to Visual Studio, I can push the Debug button which will open Acrobat for me and stop the program execution at any breakpoints I have set in the code.