In the same document, Microsoft told those running the newer Office 2016 for Mac that they must update its applications to version 15.35 or later, if they intend to upgrade their Macs to High Sierra. 'Word, Excel, PowerPoint, Outlook and Lync have not been tested on macOS 10.13 High Sierra, and no formal support for this configuration will be provided,' Microsoft wrote in a support document. Microsoft has warned users of Office for Mac 2011 not to upgrade to Apple's macOS High Sierra when the new operating system launches next month.