Can't Empty Deleted Items in Outlook, until synchronization with server is complete

Using Outlook with Microsoft Exchange. It looks like a damaged email in Outlook, stuck in the Deleted Items offline folder, which then fails to complete the Empty Deleted Items action. You get this error message:

"Outlook is synchronizing local changes made to items in this folder. You cannot remove this folder until the synchronization with the server is complete."

You can remove the problem item by right-clicking on the Deleted Items folder, then Properties, and choosing the Clear Offline Items button. Press F9 to run a sync