iOS 8 ActiveSync problem causes out-of-date meetings

iOS 8 ActiveSync problem causes out-of-date meetings

An interesting iOS/ActiveSync (EAS) issue appeared on the Office 365 community on October 22. The problem surfaced when users began to receive notifications that some of their meetings were “found to be out of date” and had been “automatically updated.”

Now, users don’t like receiving messages to tell them that something’s up with their meetings. It vexes and perplexes them as to how such a thing could occur and then leads to calls to the help desk, who probably know as much as the users as to why the problems are being flagged.

As it happens, it’s likely that the Calendar Repair Assistant (CRA) is generating the messages after it found that something was up with the meeting items in the user mailboxes. Microsoft introduced CRA in Exchange 2010 as a solution to the age-old problem of inconsistent meeting items, usually caused by updates from multiple clients using multiple protocols. BlackBerry devices were often suspected of doing terrible things to meetings while different EAS clients were often in the mix too. Even MAPI clients could munge the calendar, but that doesn’t seem to have been a problem recently.

In any case, the CRA attempts to make everything good by checking the attributes of messages and updating them as necessary. And because the CRA is a conscientious assistant, it lets users know what it has done. A fair case can be argued that CRA should stay silent as anything it tells users is likely to cause confusion and concern, but that’s how CRA works.

The question then arises as to why CRA should be suddenly so active in detecting and fixing messages that have somehow become out of date. And what is an out of date meeting anyway? As I turns out, most of the affected messages seem to be recurring events, which have always been a joy to deal with, often because of the way that different clients handle recurring patterns. For instance, KB2563324, where Microsoft lists the known set of EAS client problems, contains this interesting titbit:

Issue 1.10 - Meetings that are scheduled for the end of the month do not appear on an iOS device

When a user syncs a mailbox by using an iOS device, and a recurring meetings is scheduled to occur on the 31st of every month, the meeting does not appear on the device for those months that do not have 31 days.


iOS does not honor the 31st-day recurrence pattern in the same way that Outlook does. When a month does not have 31 days, Outlook displays the recurring meeting in the calendar on the last day of the month. Whereas iOS displays only those occurrences that land exactly on the 31st. This behavior also occurs with recurring meetings for the 29th-day and 30th-day patterns. 

The meeting out-of-date problem appears to be a recent issue because CRA has been processing calendars for years without feeling the need to highlight so many problematic meetings. All signs are that Microsoft suspects some changes made by Apple in their iOS 8.x mail app (an EAS client) might be the root cause. In fact, investigations seem to show that three separate issues are in play. According to a case update provided by Microsoft to a customer (and posted online), the issues are:

Scenario 1 – Meeting body being converted to plain text.

At this time all data that we have is indicating that iOS 8.X devices are uploading a change to the meeting that is converting the body of the meeting to plain Text.  This appears to occur any time a change is made to the meeting on the device.

Scenario 2 – Meeting body is being truncated to 500 characters.

At this time all data that we have is indicating that iOS 8.X devices are uploading a truncated body for the meeting to the mailbox. This appears to occur when the meeting is updated on the device prior to accepting it.

Scenario 3 – Multiple Calendar Repair Updates to a meeting

At this time this issue is still under investigation by Microsoft.  We are not sure of the exact cause of this issue.  Currently we have no examples of it occurring without an iOS 8.X device touching the meeting first.

It seems that the reason why CRA gets upset is that iOS clients update the time zone for meetings. There is no good reason why this should happen as a time zone for a meeting is usually fixed when first created. And anyway, only the meeting organizer should update details of a meeting. CRA notices the change and updates the meeting back to the organizer's time zone, which then causes the messages to be sent to users (logically enough) because the timing of the meeting has been changed. 

This is the first high-profile EAS issue caused by Apple iOS in quite a while. Office 365 tenants who have iOS 8.x clients that synchronize with mailboxes with Exchange using ActiveSync might check to see whether users are experiencing the problem in your environment. On the other hand, if you use OWA for iOS then this problem won’t surface because these clients don’t use EAS to communicate with Exchange.

It also seems that mainly Office 365 mailboxes are of concern to CRA as I haven’t heard too many reports of the same issue affecting Exchange 2010 or Exchange 2013 on-premises mailboxes. One reason could be that CRA is automatically enabled for Exchange 2013 and Exchange Online whereas it has to be enabled on a server in Exchange 2010. The bulk of the on-premises population is on Exchange 2010 at present so a lack of CRA enablement might account for the low number of on-premises issues.

It is problems like this that contributed to Microsoft’s decision to focus on OWA as their long-term strategy for mobile clients. Without any control over what EAS licensees do after they license the protocol, all Microsoft can do is respond to mobile connectivity problems as they arise. It’s not the greatest position to be in but given the popularity and widespread use of EAS, it will take years before the situation changes.

Update 5 November: Microsoft has acknowledged the problem in KB3015041. They suggest using OWA for IOS as a workaround. Take that advice any way you want...

Follow Tony @12Knocksinna

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