I backed up my Mac as suggested. When I called support, my main concern was that I wanted to make sure I would not lose my Chat Transcripts. The Chat Transcripts allow you to open a specific conversation on a specific date without scrolling back years. "NO PROBLEM I WAS TOLD". Well, after the update to Big Sur, my chat transcript was THere, I guess one could say, but the format was changed and there isn't an app available that opens it. It is just symbols. Spent hours on the phone with support and no luck. They also advised that re-installing bac to catalina would likely not fix the issue. Has anyone else had this issue, and if so were you able to fix it. Very simply, I have some Chat Transcripts from a friend in Hospice that I wanted to print the individual pages. This all makes me very upset, especially because I called before updating to the new os.