Thanks for reporting the issue . Unfortunately we are not able to reproduce this issue. Could you kindly provide the following information to help us nail this down :
1. Machine details which can be found by :WIN : Go to settings and Click on System and Click on About . In Windows Specifications , machine details can be found .
MAC : Choose Apple menu > About This Mac.
2. Version of Illustrator .
3.Kindly rename your Preferences folder placed in below location and share this folder with us .
MAC: /Users//Library/Preferences/Adobe Illustrator Settings//
WIN: C:\Users\\AppData\Roaming\Adobe\Adobe Illustrator Settings\
Kindly share the above with us in a Zip file at email@example.com. Please mention the title of this issue as the subject of the mail.
An error occurred while saving the commentKen High commented
Been having this issue for months now as well. Followed the put the MAC to sleep advice, reawake, and it works again. Great to know this as I hate restarting my computer and losing all that was open including all the tabs in my browser.