I had the same issue.
I had VS 2015 and 2017 installed (and project was made in UE4.15)
My solution:
- deinstalled VS 2017
- reboot
- change VS 2015 istallation: checked everything that got “c++” and “tool” in the name
- reboot
- in UE4: Editor Preferences → source code → Visual Studio 2015
- UE4 newstart
- (for safety: Check again if Substance plugin is enabled.) Build for 64 bit Windows.
- Works.
So the system gots confused by the versions and also there was no c++ stuff for VS2015 installed.
Cheese