Information
This policy setting controls whether users with the Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats installed can open Office Open XML files saved with pre-release versions of PowerPoint. PowerPoint Open XML files usually have the following extensions: .pptx, .pptm, .potx, .potm, .ppsx, .ppsm, .ppam, .thmx, .xml. The recommended state for this setting is: Enabled. The Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2016 File Formats enables users of Microsoft PowerPoint 2000, PowerPoint 2002, and Office PowerPoint 2003 to open files saved in the Office Open XML format used by PowerPoint. PowerPoint Open XML files usually have the following extensions: #x2022; .pptx #x2022; .pptm #x2022; .potx #x2022; .potm #x2022; .ppsx #x2022; .ppsm #x2022; .ppam #x2022; .thmx #x2022; .xml By default, the Compatibility Pack does not open files that were saved in pre-release versions of the new Office Open XML format, which underwent some minor changes prior to the final release of PowerPoint. If this configuration is changed through a registry modification or by some other mechanism, users with the Compatibility Pack installed can open files saved by some pre-release versions of PowerPoint, but not by others, which can lead to inconsistent file opening functionality.
Solution
To implement the recommended configuration state, set the following Group Policy setting to Enabled. User Configuration\Administrative Templates\Microsoft Office 2016\Office 2016 Converters\Block Opening of Pre-Release Versions of File Formats New to PowerPoint 2016 Through the Compatibility Pack for Office 2013 and PowerPoint 2016 Converter Impact: Enabling this setting enforces the default configuration, and is therefore unlikely to cause usability issues for most users. Note See Plan block file format settings in the Office Resource Kit for more information about using Group Policy to manage and enforce file format requirements. Also, see the 'File Block Technology' section in Chapter 4 of the Microsoft Office Security Guide for information about the Microsoft Office Isolated Conversion Environment (MOICE), which provides another method.