A few days ago, Microsoft released Cumulative Update 6 for Exchange 2013 to the world. There used to be a time where Exchange server updates were fairly safe. However, pretty much like in every other Cumulative Update for Exchange 2013, this one also includes some bugs which break functionality in one way or another. While one would say that it starts to become painful for Microsoft, I’m starting to believe it’s more of a joke.
Exchange Server MVP Jeff Guillet was the one to first report the issue. As it turns out, the Hybrid Configuration Wizard in CU6 runs just fine, but some of the features (like initiating a mailbox move from the on-premises EAC or the ability to switch between the on-prem/cloud EAC) no longer work. Although the scope of the break is somewhat limited (it only applies to customers in a hybrid deployment), one could argue it’s an important focus area for Microsoft – especially given that it’s cloud-related. Microsoft has been trying really hard (with success, may I add) to promote Office 365 and get customers to onboard to “the service”. As such, I find it really surprising that it’s the n-th issue related to hybrid deployments in such a short time. In Cumulative Update 5, the Hybrid Configuration Wizard is broken and now there’s this.
Needless to say, you are warned about deploying Cumulative Updates into production. Pretty much every MVP which announced the Cumulative Update made the remark that you should better test the update before deploying it. I would say this is a general best-practice, but given the history of recent Exchange Server updates, I wouldn’t dare to deploy one without thoroughly testing it.
This brings me to another point: what happened to testing, Microsoft? I understand that it’s impossible to test every customer scenario that you can find out there, but how come that pretty obvious functionalities like these manage to slip through the cracks? If it were a one-time event, I could understand. But there’s a clear trend developing here.
Running a service like Office 365 is not easy. More so, the cadence at which the service evolves can be really scathing. On-premises customers have been struggling to keep up with the updates that are being released in the cloud, but it seems that Microsoft itself is having a hard time to keep up too.
On a final note, I’m wondering what customers with a hybrid deployment should do. According to Microsoft support guidelines, hybrid customers are requested to stay current with Exchange Server updates. But given that this is now two consecutive update that are causing problems, one might start to wonder if it’s not better to stay at CU4 as it was the last CU which did not have any hybrid issues…
I imagine that Microsoft is working hard on a fix for this issue, even during a holiday weekend… Let’s wait and see what happens early next week!
Until then, I would hold off on deploying CU6 and revert to using CU5 with the interim update which fixes the HCW bug or – if you don’t like IUs – stick to CU4/SP1.