Hi,
Your description sounds like it's related to mods. While the symptoms are slightly different, there's a bug report about the bartender issue that hasn't fixed yet.
If you're planning to migrate your data, be sure to make a copy of your important data before you start. Keeping the original data will prevent you from losing everything. I think it would be a good idea to wait for advice from someone more knowledgeable. Since we know there's an update on the 17th, you might want to look around the Mods & Custom Content threads and bug reports in the meantime. Good luck. I hope your precious Sim starts work again.