upon startup and about 25% into startup, a "not permitted" sign appears and the iMac 27", macOS 11.6.7 freezes and fails to start. No external devices are connected. can I bypass whatever is stopping startup? is it a hardware ir software problem?
A prohibitory symbol, which looks like a circle with a line or slash through it, means that your startup disk contains a Mac operating system, but it's not a version or build of macOS that your Mac can use.
A prohibitory symbol, which looks like a circle with a line or slash through it, means that your startup disk contains a Mac operating system, but it's not a version or build of macOS that your Mac can use.
iMac 27” won’t complete startup…
