@callumfinnie18 Version.tag is the file I mentioned in the first post as the cause of your particular error. It won't turn up in a search; you need to manually open the folders described: Documents > Electronic Arts > The Sims 4.
If you can't find the file, please open Applications > Utilities, launch Terminal, and copy and paste this:
find / -name "Version.tag" 2>/dev/null
then enter. The command may take a few minutes to run, depending on the speed of your hard drive and how much data it contains. When it's done, it will list any copies of Version.tag it finds, including the full file path.
If you're still having trouble finding the file, please copy and paste Terminal's results into a post. You can write [username] instead of your actual username, but please leave everything else intact.