I just want to get rid of Monterey and get my old Sierra back. I posted to and received only copy-pasted suggestions that I've already tried.)Ĭlearly there is something fundamentally incompatible between the APFS file system and HFS that's preventing cross-pollination.

(I've been using Macs since 1986 and am very comfortable trouble-shooting. I have read a dozen articles that seem somewhat related, but haven't found one that directly addresses my issue including and and Īnd only turned to this forum in desperation.I wanted to do this but when I go to Disk Utility on the old laptop and choose 'New Image' - the 'Macintosh HD' option is grayed-out. The one thing I can think of that I have NOT yet tried is to create a new recovery flash drive apart from the Time Machine backup/boot and the dedicated boot drives that I have. Or when I choose 'Restore' to the new partition, I get the error, 'Source volume format on device is not valid for restoring' EG, 'Error 13' which appears to be some kind of Unix code. This generates error messages that appear to be some kind of incompatibility between Sierra and Monterey. I have tried within Monterey, partitioning the new SSD, creating a HFS partition in order to install Sierra on that. In all of the above, have tried 'Restore', 'Install New OS', and 'Disk Utility' in these attempts, the SSD drive doesn't appear as an option. I've tried everything, including creating a HFS partition on the SSD, but when I try to run disk utility from the external drive, it doesn't even see the SSD.īooted from Sierra Time Machine backup external drive.īooted from a dedicated external Sierra boot drive. I have a Time Machine / bootable external HD but can't work out how to erase the new SSD and put Sierra on it. I bought a refurbished 2015 MacBook so that I could continue using my legacy software, but its SSD came preinstalled with OS 10.14 Monterey.

Mac os 10.12 sierra