I tried to put bootcamp on my old mac mini which had mojave installed. it appears that the mojave portion of this disk has disappeared. it was a 500 Gig drive, and I told it to make a 100G partition for the win10 install which is the case now. But now, I don't see any way to boot into mojave. holding the option key down doesn't bring up the boot menu. and in windows I can't see any partition for the mojave portion, tho' I don't know if I should. Windows probably can't see the Mac piece. I put the usb stick in to see if I could reinstall mojave, but windows wants to format that. at a loss, right now. I think this is the reason I've run macs for 15 years and never tried to put a bootcamp windows version on.