When users try to open iCloud backup, it says “An unknown error has occurred. Please try again later.” stated that they encountered an error message and that the backup option under Settings – Apple ID – iCloud is disabled. Trying to open iCloud backup is unexpectedly blocked.
Some users stated that they fixed the problem by turning on two-factor authentication. This has led to speculation that Apple is trying to force users to use the authentication feature, but that doesn’t seem to be the case. Because two-step verification did not fix the problem for all users.
Interestingly, some users say that the backup continues despite receiving this error message. It looks like there are multiple issues affecting iCloud and will likely be fixed with the iOS 16.3. It is unknown when Apple will release the next update.