Loss of Sounds in Logic Pro 12 update

Yes.

At least Library (shortcut Y) legacy content. Still found at Library/Application Support/Logic on the main drive but not in Logic Pro 12.

NB: Everything from the new "Sounds libray" has been installed and updated.

I've done some amateur investigating and did a workaround found here:

Logic Pro 12: Missing Legacy/Ancient soun… - Apple Community

First steps

What I did

My resulting file structure