Not sure why this is marked as completed. Updating Illustrator did not help...
I might have stumbled on a solution when I ran into a permissions issue updating homebrew. The solution was to issue (on the command line via Terminal.app):
sudo chown -R $USER ~/Library/Caches/
Suddenly Illustrator started working correctly again. Looks like there was a ~/Library/Caches/Adobe folder that this command was also resetting the permissions of, so maybe that accidentally fixed it. Not sure how the permissions got screwed up. Maybe this is apple's fault (probably!).
Not sure why this is marked as completed. Updating Illustrator did not help...
I might have stumbled on a solution when I ran into a permissions issue updating homebrew. The solution was to issue (on the command line via Terminal.app):
sudo chown -R $USER ~/Library/Caches/
Suddenly Illustrator started working correctly again. Looks like there was a ~/Library/Caches/Adobe folder that this command was also resetting the permissions of, so maybe that accidentally fixed it. Not sure how the permissions got screwed up. Maybe this is apple's fault (probably!).