Did you follow the Troubleshooting Errors in Word Processor Documents steps? What happened at each step?

Unless you deleted everything in your document and still get the error, you haven't completely followed the steps. You also don't seem to be logging the error actually occurring.

See the Debug ID instructions. You don't seem to have actually triggered the action while logging was enabled, so we don't know what error you're getting.

Does this happen in a new, completely empty document, or only an existing document that you've cleared completely?

OK, if it happens in new, empty documents, that troubleshooting page isn't relevant at all. See the first line:

If you get an error trying to use Zotero in a new, empty document, see Word Processor Plugin Troubleshooting.

I'm not sure exactly what you're doing, but you still have yet to actually log the error in question. Can you just trigger it and then provide a Report ID, not a Debug ID?

This command is not available because no document is open

Is the document stored in OneDrive?

OK, so this was Step 7 on the troubleshooting page you said you followed:

If using OneDrive on Windows, save the copy of the document to your local hard drive, or try renaming the file to remove any spaces in the filename. OneDrive is known to interfere with the plugin for some people.

It's about the spaces in the filename. This error occurs for a document stored in OneDrive with spaces in the filename. That's it — nothing else on any other page is relevant. Either remove spaces from the filename or move the file to the local disk.