Hi chimmiecrabcrab,
Welcome to Apple Support Communities. We understand that you're having an issue with opening your documents through Finder. We'd like to help.
From what you've described, it seems like Finder is finding an alias of your documents instead of the original file. Are you able to search for the files for the original? If not, do you have a backup of your data from before the update? You may need to restore from your backup to access these original files.
This resource can help you with removing aliases after you locate the originals: Create and remove aliases on Mac
Take care!