This has been fixed in recent release. Please upgrade to latest version of Illustrator to get the fix.
An error occurred while saving the commentKelly commented
I am getting so frustrated with Adobe. It seems that this problem consists across the board. Something happened (I'm guessing when I updated my computer to High Sierra) and now all of my keyboard shortcuts are gone. I don't even use any custom codes... just the standard codes. I find myself smashing the keys trying to get the shortcuts to work only to remember that it doesn't work in illustrator. My shortcuts work fine in Photoshop, Word and other programs... just Illustrator giving me ****. I tried to add my regular shortcuts in the Keyboard shortcuts tab but is says "The key pressed cannot be used as a shortcut." I pressed Command Z to try to reset the undo button.