Thanks for reporting this issue, Illustrator team really appreciate this.
We are able to reproduce this issue and it is currently under review.
An error occurred while saving the commentMelissa Fraser commented
SOLUTION: go to Creative Cloud chat support and have a rep remotely log onto your machine and have them fix it in under 5 mins. He fixed my corrupted system preferences and I couldn't have solved this on my own. I'm guessing it was so quick as many MANY others were experiencing the same difficulties.
So glad I did it! Good luck!