The work item could not be moved to the sprint or backlog because an error occurred when attempting to update the iteration ...

The work item could not be moved to the sprint or backlog because an error occurred when attempting to update the iteration path of the parent work item. You might not have the necessary permissions to edit the work item, the work item might have been modified by another user, or you might have lost connection to your server. Refresh your browser, and then try again.