Can't launch Cubase SX 3 on Snow Leopard anymore, since I upgraded to Cubase Pro 10.5

I’ve already tried this with no luck, both with the eLicenser software version linked in the Steinberg Support Team post (6.3.6.1098) and the latest available version compatible with 10.6 Snow Leopard (6.7.1.8151 from https://www.steinberg.net/en/company/technologies/elicenser.html#old_elcc).

All I get is an error message saying that the currently installed version of the eLicenser Control software is too old.