JSF Warning: WARNING: FacesMessage(s) have been enqueued, but may not have been displayed. ..

Warning raised from com.sun.faces.renderkit.RenderKitUtils.renderUnhandledMessages (Mojarra) when while iterating through the list of unhandled messages none of them can be rendered. This problem can occur in production mode because in the project (application) which is in production stage the unhandled messages are suppressed. In development stage the problem doesn't occurs.