The update is the Exchange Server 2010 SP3 Update Rollup 8, one of several Exchange Server update packages released yesterday. There were also update packs for Exchange Server 2007 and 2013, as well as language packs for Exchange Server 2013 Unified Messaging.
Now Microsoft says that a problem in the update affects the ability of Outlook to connect to Exchange. It has been removed from the Download Center and other channels until a fixed version is available. Microsoft recommends that customers who have already deployed the update perform a rollback on it. The rollback is the only action necessary in order to restore any lost connectivity from Outlook.
The security updates for Microsoft Exchange yesterday had actually been delayed a month from the November Patch Tuesday.
Problems with released Microsoft updates have become a common occurrence over the last two years. Microsoft had to recall another buggy Exchange update in August 2013. The buggy code in that update turned out to be in an embedded component written by Oracle, but it was still part of Exchange Server and distributed by Microsoft. That same month a Windows Media Services update had to be withdrawn and reissued. There were several other withdrawn updates in 2013. Several updates in the Summer of 2014 wreaked havoc on users' systems and had to be retracted In September the same happened to a Lync update.