You can make a difference in the Apple Support Community!
When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.
When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.
With my computer this is caused by the update of Catalina (the program!) - Reseting fusion drive will not help when reinstalling Catalina, as the update will generate the message again.
iMac 27″, macOS 10.15
It appear you have to Repair the drive, Erase it, or use an exteranal Drive or SSD...
https://forums.developer.apple.com/forums/thread/655840
MT mapping is not completely referenced - Apple Community
... that's what I thought, too. (done erase, resetFusion, reinstall via USB, have SSD harddrive, too. Now I know it will not work as the problem reappears when updating Catalina.
current theory: the incorrect mapping is related to the hidden installer ESD. I know its there, but cannot access it. (mac can reinstall os without usb using cmd r...)
Try installing to an external SSD or drive.
warning: MT mapping is not completely referenced.
