When I first got KM on my old Mavericks machine I didn’t like the app switcher and disabled it. Now I’m on a Yosemite machine and the UI lag is killing me. I’d like to have KM’s app switcher mapped to cmd+tab but the OSX switcher always wins out.
The Command-Tab “hot key” for the system switcher is a bit tricky, in that it is not actually a hot key in the system, and so Keyboard Maestro use the event tap system to bash it in to submission.
If you have reenabled the Application Switcher with the Command-Tab hot key, it should “just work”. But because of the event tap system, it is possible it might not in some odd cases, due to the order of patching of the event tap.
First, make sure that the Application Switcher action really is active and enabled and has the right hot key.
If it is still failing, try restarting the Keyboard Maestro Engine and if that still does not work, restart the Mac.
Good 'ol reboot did it. Thanks!