News

Exchange Server Cumulative Updates Unlock .NET Framework 4.6.1

• By Kurt Mackie
• 06/21/2016

Microsoft released cumulative updates for Exchange Server 2016 and Exchange Server 2013 this week, clearing the way for .NET Framework 4.6.1 use by organizations.

These cumulative updates, namely Exchange Server 2016 Cumulative Update 2 and Exchange Server 2013 Cumulative Update 13, are currently available at the Microsoft Download Center. Both include the usual fixes, as expected with Microsoft's cumulative update releases, but they also include "updated functionality," according to Microsoft's announcement.

Microsoft Unlocks .NET Framework 4.6.1
Perhaps the most notable updated functionality is the ability to use these servers with the latest .NET Framework 4.6.1 solution. In February, Microsoft had warned organizations to block the use of .NET Framework 4.6.1 with Exchange Server because it wasn't supported and would likely cause problems. Now, Microsoft is waving the all-clear signal:

Support for .Net 4.6.1 is now available for Exchange Server 2016 and 2013 with these updates. We fully support customers upgrading servers running 4.5.2 to 4.6.1 without removing Exchange. We recommend that customers apply Exchange Server 2016 Cumulative Update 2 or Exchange Server 2013 Cumulative Update 13 before upgrading .Net FrameWork.

However, there's no rollback option if things go awry when upgrading from .NET Framework 4.5.2. IT pros would have to perform a reinstall, Microsoft's announcement warned.

There's an installation order, as well as some post-update patches to apply, when upgrading to .NET Framework 4.6.1. In addition, those who blocked it will have to remove the block. Those precautions were highlighted by Jeff Guillet, a Microsoft Certified Solutions Master and Exchange MVP, in this blog post. Guillet also recommended using a .NET Framework optimization script at times to make things run faster.

Another caveat is that there's no support for Exchange Server 2010 to use .NET Framework 4.6.1. "It still isn't supported for Exchange 2010 and most likely will never be," Guillet wrote.

Other Cumulative Update Perks
Some PowerShell cmdlets were updated. The "New-ExchangeCertificate" cmdlet now produces SHA-2 certificates by default. The "Get-ExchangeServer" cmdlet now reflects server roles, such as Mailbox or Edge.

Microsoft's announcement indicated that a "modern public folder" issue gets fixed with the cumulative updates. The engineering team also added BitLocker support in the "Disk Reclaimer function within AutoReseed."

Precautions
The announcement mentioned that a workaround is needed for organizations wanting a local language setup. Microsoft plans to address this issue in future cumulative update releases.

Installing Exchange Server 2016 Cumulative Update 2 includes Active Directory schema updates. However, IT pros need to have the requisite schema update permissions for the installation to succeed.

On the other hand, installing Exchange Server 2013 Cumulative Update 13 does not include the Active Directory updates, but it "may add additional RBAC [role-based access control] definitions." Microsoft recommended that "PrepareAD should be executed prior to upgrading any servers to CU13." PrepareAD apparently is a setup option that gets specified at the command prompt.

Microsoft's announcement also warned IT pros to ensure that "the Windows PowerShell Script Execution Policy is set to 'Unrestricted' on the server being upgraded or installed," which will help ward off possible "installation issues."

Lastly, Microsoft's announcement stressed that it's a requirement for hybrid Exchange environments to apply the most current cumulative update. However, the use of "the prior" cumulative update is OK, too, which seems to be a bit of a concession on Microsoft's part.