Hi Seedy,
I did a test and removed a folder from the Official folder. It allowed the sim to boot up, and gave me the option to install the missing package or ignore (this is at the main sim menu). Clicking ignore allows you to sim without issue (in my case I had removed the Caravan folder from Official). However, clicking install will take you back to the checking for updates missing essential packages screen.
So, if I’m understanding correctly, it seems to be something in the download/install process that’s having a hiccup.
Cheers