Apple has acknowledged a bug in iOS 6.1 that causes devices to experience syncing issues with Microsoft's Exchange Server, and has promised that a fix is on its way.

On its support page, Apple has published a new article that explains: "When you respond to an exception to a recurring calendar event with a Microsoft Exchange account on a device running iOS 6.1, the device may begin to generate excessive communication with Microsoft Exchange Server."

"You may notice increased network activity or reduced battery life on the iOS device," Apple continues. "This extra network activity will be shown in the logs on Exchange Server and it may lead to the server blocking the iOS device. This can occur with iOS 6.1 and Microsoft Exchange 2010 SP1 or later, or Microsoft Exchange Online (Office365)."

Apple says that it has identified a fix for the bug that will be made available in an upcoming software update.


In the meantime, Apple suggests that iOS 6.1 users can avoid encountering the bug by not responding to an exception to a recurring event on your iOS device. An exception is a change to a single instance of a repeating calendar event.

Those who have been affected by the bug are advised to disable and re-enable the Exchange calendar on your iOS device by going to Settings > Mail, Contacts, Calendars, selecting the Exchange account from your Accounts list, and then turning the switch for Calendars off. After waiting ten seconds, you can turn the Calendars switch back to on and the problem should be fixed.

Apple released an iOS 6.1.1 update for iPhone 4S users on Tuesday to address a 3G issue that was affecting some users after they had updated to iOS 6.1. The update has not yet been made available for other iPhones.

Apple initially released the iOS 6.1 update to consumers on 28 January, bringing a few minor – but welcome – changes to the software including the reinstatement of iTunes Match features, a Reset Advertising Identifier and more LTE coverage.

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