I'm having the exact same problem with my Mac Mini (late 2012) running OS X 10.8.6
Muse said it was installed in CC, but it is nowhere to be found.
Can't manually install Muse because of a problem with AIR
Can't update AIR because I don't have administrator permission (even though I AM the admin)
Deleted all AIR files, tried reinstalling AIR. No luck. Same error message
I've tried all the same fixes with no luck. I really wish there was a solution to this problem!