Elite: Dangerous PvE - Mobius

1. Right click Elite Dangerous in your Steam library
2. Select ‘Properties’
3. Go to the ‘Local Files’ tab
4. Select ‘Browse Local Files’
5. Select the EDLaunch.exe
6. Login if required
7. Select Elite Dangerous: Horizons – Engineers Beta [2.1]
8. Witness how the Upgrade button is now blue and ready to ‘Upgrade’
9. Select the ‘Upgrade’ button and you should be good to go

From here: https://forums.frontier.co.uk/showthrea ... 509&page=4

Worked like a charm. Still quite irksome how mental the Frontier team is at the launcher situation. My system can be overrun with Elite installs or copies, thanks to how it handles data.. Though, now that Horizons ISN'T a separate game, that's saved a fair bit of space..