How can I stop the "monitor feedback" notice from popping up?

GarageBand 10.1.2: This more-than-annoying notice keeps popping up when I'm recording NOTHING and--even weirder and even more than more-than-annoying--there aren't even any vocal tracks OR "live" instruments in the tune at all thus far!?! Help?!? Once again, I'm ready to go back to my older MacBook Pro with SNOW LEOPARD, you know, back when GB was cool and made sense, not cents!