Command and Option keys not working on one keyboard (not hardware) I am using a PC keyboard on my Mac. Today, it stopped recognizing the Command and Option keys.

This likely happened because I experimented with Karabiner and Yosemite Modifier Keys yesterday.

I have tried:


Resetting modifier keys to defaults.
Checking private.xml through Karabiner (blank).
Undoing my settings on Karabiner.
Uninstalling Karabiner entirely.
Restarting OS X.


None of these things have worked. Keyboard Viewer is not registering key presses on Cmd (Windows key) or Option (Alt). Any ideas?
I opened "Keyboard Preferences" and clicked on the Modifier keys. Clicked on "Restore to defaults". And the modified keys started working again. After that I switched the modifier keys back to my preferred set. And things are still working. Feel quite good. It saved me an avoidable reboot.

I am in such a similar issue often. The problem used to get fixed after restart (probably will also work, after logout/login -- did not check). Today it happened again. I tried the defaults method above and it worked.