I am taking a class and saved my project to the cloud to work on in the next class. The following day, I opened my file, and it froze. I had to close Illustrator and reopen it. When I did, my file was no longer in my cloud, or saved anywhere else. It literally deleted my file and I have to redo my project before I can attend my next class. Thankfully the class is recorded so I can take it at a later time. I hope this does not happen again. I know this has been happening to others as a few friends of mine who use illustrator are having the same issues as well.