I am unable to download the Witcher 3 GOTY Classic files via Galaxy. When I try I get "Download failed", but no details as to why it failed. Could it be the server(s) are maxed out? Are the links incorrect?

The links for GOTY/Classic are currently pointing to the wrong files (both in galaxy and ion the website

you can wait for them to fix them, or ...

Steps to workaround the problem
Login to the website via your browser, and right click open the download link in a new tab
You will get a 404 error
in the address bar go to the very end and you will see something like:
<long URL ending with> .../witcher_3/goty/classic/setup_the_witcher_3_wild_hunt_goty_1.31_(a)_(9709)_(g).exe
delete the part that says _(g) then press enter
you should get a download prompt, and proceed normally for that file.
repeat for all the rest

Thanks for the tip. By the time I got to trying it, GOG had updated the Galaxy links. Except for "Part8" (aka, setup_the_witcher_3_wild_hunt_goty_1.31_(a)_(9709)-7.bin ). And I just noticed now that these are supposed to be level 1.32 but the file names indicate 1.31. Hahaha. Back to GOG support.

only thing different from 1.31 to 1.32 is chinese language support.

Not really a high priority unless someone in the house speaks or is trying to learn chinese