Error occurred while I tried to generate C++ Project

I am getting that same “Verify that Common Tools is installed” message even though I’ve verified that both “Common Tools” check boxes are checked in the Modify section of Visual Studio’s custom installation dialog.

I get this message in the log output any time I try to create a new C++ class in any project, even a brand new one with nothing in it. I’m on 4.12.5… Unreal pops up a dialog half way through trying to create a C++ class that says some resources failed to load. If I close the project, I get another error any time I try to open it again. I’m new to Unreal. Is this a common newb issue?