Hi zoeprax
I'm not with Laminar Research, just a fellow simmer in the UK.
1. Please advise how many hard drives you have in your PC?
2. Which drive is your MAC operating system installed on i.e. C: Drive?
X-Plane 11 is normally installed on the local C: Drive i.e. C:\X-Plane 11, with the X-Plane 11 executable file located in the C:\X-Plane 11 folder
Regards