Yikes! Mac starts typing option-characters

Twice in the past three days, my 2013 27" iMac started typing all keys as if the option modifier was being held down. I don’t think it’s a bad keyboard, because I unplugged mine and connected a Bluetooth keyboard, and the problem was still there.

I first noticed it when I tried to Cmd-Tab to switch apps and nothing happened. I have to restart to get back to normal. I reset the PRAM after the first incident, but 2-3 days later it happened again.

I’m suspicious of the Karibiner Elements app, since it’s the only thing I know of that’s taking liberties with the keyboard. But I’d been using it for 2-3 weeks before this happened, and the only thing I’ve done with it is set up the caps lock as the Shift-Ctrl-Opt-Cmd hyper key.

Other items in the mix: Keyboard Maestro, Stream Deck, and Text Expander (but its expansion was disabled when this happened)

Any ideas? This is a little frightening.

Crumbs/dust/hair in the keyboard, maybe.

Have you checked your Accessibility preferences? Maybe you are accidentally enabling the sticky keys.

Thanks for the idea. Enable Sticky Keys was unchecked, and when I checked it to activate sticky keys and hit option, a graphic popped up on the right edge of the screen, which hasn’t been the case. I’ll keep digging.

Thanks, bowline, but I got the same result when I unplugged the wired keyboard and connected a Bluetooth one.

Sorry, I’ve been missing details in people’s posts today.