Update 8/26/14: changed the resolution to include the release of Exchange 2013 Cumulative Update 6 (CU6).
An important update is now available to resolve issues customers are currently experie...
Updated Jul 01, 2019
Version 2.0
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The fix requires a reboot of the Mailbox server. Why wasn't this issue fixed on the Cloud side instead of requiring customers to take down their systems?
The Fix, per Tier 3 support has also caused issues with clients servers, but there is no statement from Microsoft that the fix is eligible for free support in case of catastrophic failure of the Mailbox server after installation.
This is a direct quote from Tier 3 support regarding the fix "My sincere apologies, but we’re seeing some issues with the fix that was created to address this issue. We don’t want to risk breaking your existing environment. So, please stand by as we work to
resolve the issue(s) with the current fix. I will try update you as soon as possible."
Also if a customer does not have SP1 installed, they cannot use Office 365 hybrid, which directly contradicts the current 365 Hybrid documentation on Technet that states that the only CU needed for Hybrid configurations is CU1.
http://technet.microsoft.com/library/hh534377(v=exchg.150).aspx