When inserting a citation from EndNote 20 or 21 I get the error: 'Cannot edit range'

The exact error message:

Windows: Cannot edit Range

Mac: A COM exception occurred. Cannot edit Range.

The Mendeley Word add-in is causing this conflict. Unchecking or remove the addin is not possible.

For Windows

First make sure the 'hidden files and folders' are visible (Menu View > Options) in Windows.

1. Find the correct path via MS Word 'File > Options > Addins> Word or Com addins'.
2. Then look for the path of the Mendeley add-in (e.g. Mendeley-word2016-1.18.dotm or Mendeley-word2016-1.19.dotm) in the same screen. Usually the path is: C:\Users\[User Name]\AppData\Roaming\Microsoft\Word\STARTUP.
3. Close MS Word and go via Windows Explorer to the above path.
4. Remove the Mendeley Word add-in.
5. Start MS Word and the problem should be solved.

Alternatively, uninstall Mendeley (and the add-in with it). EndNote has many PDF file and folder import, PDF-handling and Find Full-text options.

For Mac

1. Usually the path is:  /Users/[User Name]/Library/Group Containers/UBF8T346G9.Office/User Content.localized/Startup.localized/Word
2. Close MS Word and go to the above path. To see this (hidden) folder, please use the Finder and Go and hold down the [OPTION] (ALT) button and click the appearing 'Library' item.
3. Remove the Mendeley Word add-in (e.g. Mendeley-word2016-1.18.dotm or Mendeley-word2016-1.19.dotm).
4. Start MS Word and the error should be solved.

Alternatively, uninstall Mendeley (and the add-in with it). EndNote has many PDF file and folder import, PDF-handling and Find Full-text options.

A similar behaviour may be seen with other third party add-ins e.g., like Zotero. Please follow a similar approach to disable (uncheck) or uninstall other third party add-ins. Clicking the third party plugin, will show the exact path to the add-in/plugin file(s).