So.... the windows version of RPGMZ doesn't build the Mac version too well.
I've prepared a new one, built natively on a Mac I borrowed.
I've replaced the one here, and you can also download from:
https://mega.nz/file/XmAF1bbI#xOMf0Hfmg7mR_CH1kLPGvXNwbFcySt5uUt3v4VSxYp8