I got it working!
Thanks to Steinberg US customer support.
I got a new activation code and download link, as well as instructions. What I forgot about was that you have to enter the activation code in elicenser first, or else it won’t work. 
I got confused, I guess, a lot of other software prompts you to activate/register, and it never occurred to me to just enter the activation code without being prompted to do so.
My bad.
But Steinberg, maybe the download should come with a readme containing installation/activation instructions? Every company does things differently, and half the time I can’t remember who does what how.