I'm trying the reinstall Mac OS Monterey 12.6.7 through recovery. I get this error "com.apple.buildinfo.preflight.error error 21". Does this error have something to do with my wifi and firewall in my cable modem. I did check the drive with first aid, and everything is fine there. Just trying to reinstall the Mac OS through recovery mode. Any suggestions?
iMac 27″
I was able to use "Command+T" on startup and connect the computer to another Mac. The hard drive showed up on the other computer where I was able to transfer all document & image files to an external hard drive. I did not lose anything. I like how Apple created the Operating System to keep the OS separately away the document+image+video files.
I have exactly the same problem, and I think it's not because of the network or something, I think that's because of the target disk for installing macOS is broken (on software). I suggest you contact an advisor at https://support.apple.com for solving this problem.
Maybe one of these will provide insight: com.apple.buildinfo.preflight.error error 21
You know what, I think for Intel-based Macs, you just have to press "T" on startup to get into target disk mode, instead of "Command + T"
com.apple.buildinfo.preflight.error error 21 on iMac in Recovery Mode reinstalling Mac OS Monterey
