A change to the previous version of Microsoft's AutoUpdate utility caused updates to break in Office 2011 for OS X. A fix is ready for download. AutoUpdate 3.0.5 was installed with the last Office update a few days ago. Microsoft has backed off from the mess it made with a new version of AutoUpdate you can download now. The problem only happens if you're using both the Office 2016. Microsoft Office for Mac 2011 is a version of the Microsoft Office productivity suite for macOS. It is the successor to Microsoft Office 2008 for Mac and is comparable to Office 2010 for Windows. Office 2011 was followed by Microsoft Office 2016 for Mac released on September 22, 2015, requiring a Mac with an x64 Intel processor and OS X.

08 Jul macOS Catalina Incompatible with Microsoft Office 2008 & Office 2011

If you are planning on upgrading to Catalina in the fall when it is released, why not save yourself some grief and upgrade to the 2019 version of Office now? The “perpetual” version is $149 (for Word, Excel and PowerPoint) and Office 365 starts at $69 a year.
Can I Use Microsoft Office 2011 With Catalina
