Mendeley Word Plugin Problem

How I resolved the issue:

1.) You can download previous version here https://docs.microsoft.com/en-us/officeupdates/update-history-office-for-mac (scroll way down for a list of the previous versions). Then download the version you like, I just reverted to version 16.20 as mentioned above. 

2.) Go to your applications folder and delete all Office applications. 

3.) Download and install package. I also went offline so that it wouldn't check for a new version during installation (this might be unnecessary). 

4.) Don't forget to deactivate auto-update: Go to help -> Check for updates -> Choose "Automatically Check" or "Manually Check". 

*Screenshots are from the Dutch version.

After clicking the References tab in the Word Ribbon, an error menu pops up.

Click the (dotted) button at the right, will be 'Search errors' or something in English Word distribution, to open the Visual Basic Editor.

Then look up 'MacIpcClient' in the menu 'Project - MendeleyPlugin' at the upper left of your screen and double-click.

The following window will pop up, activate this window by clicking on the text.

Press ctrl (or cmd for mac) + F for the Find menu and click Replace... menu (or open Find and Replace with cmd + shift + H for mac).

Search for "libc.dylib" and fill in "/usr/lib/libc.dylib" in the Replace field and click 'Replace all'.
Click 'OK' on following pop-up windows.

Close Find and Replace menu.
Save the adjustments by clicking the floppy icon in the upper left and close window of Visual Basic Editor.

Finally, restart Word