Can you try deleting the ByURL view in bookmark.nsf? To do that:
- Go to the user's Client and open the Workspace, then highlight the bookmark icon.
- Hold down the CTRL and SHIFT keys, and from the menu, select View > Go To > (ByURL). Note: This is a hidden view.
- In the same view, select all documents and delete them.
- Restart the Client and check if the issue will reoccur.
Hope that helps!