I am experiencing the exact same problem. It started a couple of weeks ago after an update. My company files are 137,000kb and 57,000kb. I have restarted my computer multiple times. I have tried manual updates but I am fully up to date. The only way I could find today to switch companies was to close QB, then double-click on the .QBW file in my C drive folder. The company opened, and then I was able to switch to the other company as it has always done for the last 25 years. I am using QB Desktop Pro Plus 2023.
