Thanks for reporting this issue, Illustrator team really appreciate this.
Unfortunately we are unable to reproduce this issue in house, Kindly help Illustrator Team to nail this issue down further:
Kindly provide the exact preferences you are using and the data from below mentioned location .
Mac:- /Users//Library/Preferences/Adobe Illustrator 2X Settings
Win:-C:\Users\\AppData\Roaming\Adobe\Adobe Illustrator 2X Settings
Share the above information with us at ShareWithAI@adobe.com in a Zip file. Please mention the title of this issue as the subject of the mail.
Thanks and Regards
An error occurred while saving the commentSteph commented
Same thing here. Even on different computers EVERYTHING gets wiped. The workspace selector doesn't come up, and no Minimize or Close buttons either. I get everything back from the Window>tools/workspace/ALL THE PANELS, but every time I close the program and start another day everything resets to a blank screen with the "Dock" showing up on my second screen and nothing with no buttons. I've even tried exporting settings, but importing them back changes nothing.