Last week I put together a few yard signs for work and received an email from a coworker who wanted a few edits made to the signs, but when I went to open up my project file to make the edits it had reverted to an older version of the project? I had saved PDF versions of the yard sign designs that I showed to my coworker and that showed the most recent version, but the AI project file does not. I ended up going back in and redoing all of the text elements and saving both the AI file as well as a new PDF file of the updated sign designs, but again the AI file did not save with my updates and went back to the old version of the file. I have not had this issue until today, my files were saving just fine last week and any time beforehand. Any suggestions on how to fix this?