DFU Restore error 21 during macOS update
When I was updating macOS, it went to DFU mode. And then, while restoring, I get error 21. Please, tell me what is the actual issue?
[Re-Titled by Moderator]
Original Title: DFU Restore error 21
togadiyahiren wrote:
When I was updating macOS, it went to DFU mode. And then, while restoring, I get error 21. Please, tell me what is the actual issue?
[Re-Titled by Moderator]
Original Title: DFU Restore error 21
You can ref: iOS update and restore errors - Apple Support
Try a different rescue mac or a different data cable and compare your results.
ref: How to revive or restore Mac firmware - Apple Support
In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test /assessment
Make an appointment for a "hardware issue"
Genius Bar Reservation and Apple Support Options - Apple
Outside the USA
Contact Apple Support - Apple Support