Apple Says It's Fixed the iCloud CloudKit Synching Bug

Apple has finally fixed an ongoing CloudKit bug that caused problems with iCloud syncing for many third-party developers and their users.

In November 2021, developers began reporting CloudKit errors that would cause previously-functioning sync features to stop working. The ongoing issues even led to some developers dropping sync features altogether. Now Apple has confirmed looking into the bug and stated its engineers have implemented a fix.

The bug often resulted in users receiving a "Request failed" 503 error or "Service Unavailable," even when the developer didn't change the underlying app code. The result was that many users could not properly sync their data between devices.

With no luck in reproducing the bug to try and solve the problem, developers reached out to Apple for help but were often redirected to Apple's Feedback Assistant. Apple did confirm looking into these reports but did not comment on why developers were being told to contact Feedback Assistant instead of Support.

"The errors seen here resemble request-throttling that may be affecting a specific user, or the container as a whole," Apple stated in its reply, "An underlying issue caused an elevated number of these error responses to be returned to your CloudKit apps in certain situations, and has since been resolved." It went on to say, "You should no longer see these error messages from the CloudKit console or from devices running your app."

If you've encountered this bug before, your apps' sync features should begin to work properly now. Though if the developer shut off sync features, you'll need to wait for them to be re-implemented first.