There is a Companion and Emulator section in this FAQ:
It includes a few alternative emulators you can try like GenyMotion, and
school-specific installation links.
Regarding the Companion self-update process, it's finicky in that it
has two parts that run in two different windows on your PC,
with one part sometimes stalled waiting for a response in the other window.
I'm guessing that's what happened to you.
I like the Genymotion emulator, which can install a fresh copy of the Companion .apk file
just by dragging it into its home screen.
ABG