DUST2DEATH
♥♥♥♥♥ Fox
You need the new Multi Platform script that includes Mac/Linux support.I have not and never used a Mac, on my computer it appears fine, so I think it is some incompatibility with the Mac, I will try to research on the subject
You may or may not also need to reinstall unity to include Mac/Linux features/functions.
Grab from OP: https://7daystodie.com/forums/showthread.php?97386-Updated-Asset-bundle-export-script-for-Unity-2018-and-A17