This is really strange.
When I press Ctrl1 the view should switch to Back View, according to my preferences.
It's even listed correctly in the menu:
It doesn't do anything.
Ctrl3 for Left View is working, and Ctrl7 for Bottom View is also working.
I use Emulate Numpad as a standard always, even on machines where a numpad keyboard is available.
My OS is macOS Sierra. Blender version is 2.79.
The most bizarre thing is that it still doesn't work even after I Load Factory Settings (and re-enable Emulate Numpad). This makes me think it might not be my settings at all. (Possible bug?)
My Ctrl key and my 1 key are working just fine for all other uses, in Blender and in other apps.
It's really a hindrance when modeling. Any ideas?