SE/30, 4MB memory, OS 7.5 installed (working fine)

Apple external CD-ROM drive (also works fine)

I expected when I connected the CD drive to the Mac and booted it'd recognize a CD I had in it. But it didn't.

But I know various OS versions are finicky with various drives, so I instead tried copying CD Sunrise v2.2c into the extensions folder. But when I restart I see it trying to load the extension but it gets the X through it.

What am I missing?

Hard drive is terminated, ID 0, Cd drive is terminated, ID 3.