Document is either deleted or not currently accessible

If you are attempting to use the 32-bit Office 2008/2011 suites on Catalina, you certainly won't have functional applications, or the ability to open MS documents in those applications. If that is the case, you need to decide on upgrading to Office 365, the single-purchase Office 2019 for Mac, or the free LibreOffice Suite — all of which are 64-bit application suites.

It is customary for sandboxed applications to maintain a ~/Library/Containers/com.microsoft.* folder and its own application support and preferences content. Additionally, there may be a ~/Library/Application Support/Microsoft folder with other data in it. The tilde (~) is a shortcut replacement for /Users/yourname.

I seem to miss the com.microsoft.Word.plist file that the poster said I should move to the Desktop to solve the issue.

Download and run Find Any File to search for the file: 

1 - Name is com.microsoft.Word.plist

Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.

FAF can search areas that Spotlight can't like invisible folders, system folders and packages.

You don't have this?

Then while in your Home folder use the View ➙ Show View Options menu and then check the Show Library Folder checkbox. Then the Library folder will be visible.

Find Any File is Shareware so you can use it for free or not.

Look in the Library/Preferences folder for the microsoft preference file to remove, com.microsoft.Word.plist.

Because your Library folder is still hidden. Open a Finder window and if your home directory is in the Favorites list, click that. Then press command+J and select Show Library Folder. Now it will appear in your Finder Go menu.

You can press shift+command+G to bring up the Finder's Go To Folder dialog. There, you can enter tilde strings, e.g.:

~/Library/Application Support

~/Library/Containers