Changing modifier key assignment, different for different programs

Well Karabiner-Elements is not ready for prime time. It permanently f***d up Sierra. I will probably have to reinstall Sierra.

So is there a way using Keyboard Meastro to change the Right Option key to mean “Control”?

Also is there a way to do this in only some apps?

No.

This is below the level that Keyboard Maestro operates at.

Thanks Peter, I will look for some other way to do it.

What has it done exactly?

I’m asking because I also had Karabiner Elements installed for a short test. Maybe some of my Sierra problems are related, without me knowing…

I apologize for posting that… I was jumping to conclusions. I’m new to Mac so I am not familiar with uninstall procedures. (On Windows generally one runs the “uninstaller” and the program is gone.) What I learned is that Karabiner-Elements installs some daemons and user-agents, and I needed to delete those plists before it stopped messing things up. It’s fine now.

What it did was mess up OS X’s ability to recognize external keyboards. In fact, when I tried to identify a particular keyboard, OS X told me that it was the internal keyboard. This seemed so “buggy” to me that I figured something had been deeply corrupted, leading me to post the above.

I didn’t realize this kind of behavior could result from the K-E daemon still running until later. I didn’t even know K-E had installed a daemon.

Thanks for the info.

What I learned is that Karabiner-Elements installs some daemons and user-agents, and I needed to delete those plists before it stopped messing things up

Thanks for that info, too. (If I recall correctly, Karabiner Elements has an Uninstall button. Did you use the Uninstall or did you just trash the app?)

Trashed the app.