Having seen this, from the SDA I ran the installers here:
Of course I should have known better; just wanted to be up to date!
I got the error when I next launched Dorico Pro 2 as in the lower half (black) of the attached grab.
Have I now put things right, please, by removing the files as in the upper half (Finder) of the same grab?
I know I should have left well alone.
Would I be better to reinstall all my HALion files from scratch?