Create a new project using the D/C++ project wizard. (close and reload the project solution to cause the project explorer to refresh) Project -> Properties -> General DCompiler selection is no longer in the menu, can't switch between DMD/LDC anymore
Did you install something else that adds to the Geeneral page? IIRC the Intel compiler does that, and that doesn't cooperate well because there seems no way to add to this page, you can only replace it (Visual D takes a snapshot of the default at installation). Does reinstallation of Visual D help?
I haven't installed anything else, and certainly VisualD was the most recent thing I've installed... and I'm often reinstalling VisualD (because i've been testing all the pre-releases).
For the record: this is caused by the general project page being overwritten by another extension in the same way as Visual D does. There is no known way to combine the two extensions.
As a workaround, I added the option to the D Compiler pages, too. See https://github.com/dlang/visuald/releases/tag/v0.52.0
This works surprisingly well!
It also turned out to be rather simple (after a lot of investigation in the other direction). I'm considering removing the option from the main page as it would simplify installation and avoids other issues, too, like hiding changes to the General page after Visual D has been installed.