I plan to start a general topic on the new macOS 10.13, High Sierra. but I just ran across this article by Microsoft that may be of interest to a number of you, including me.
###Microsoft Office support for macOS 10.13 High Sierra
Looks like support will be provided for the current version of Office, but it is not clear for Office 2011:
Office for Mac 2011
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.
All applications in the Office for Mac 2011 suite are reaching end of support on October 10th, 2017. As a reminder, after that date there will be no new security updates, non-security updates, free or paid assisted support options or technical content updates. Refer to the Microsoft Support Lifecycle for more information.
I guess this is to be expected, and I'll have to deal with it when I upgrade to High Sierra.
I'm still running Office 2011 on macOS 10.11.6 (El Capitan).