Local error does not occur: Uncaught TypeError: Can not read property 'getAttribute' of undefined

I'm having trouble loading a combo, location works, but in the development environment it gives the following error ... Uncaught TypeError: Can not read property 'getAttribute' of undefined

            <h:outputLabel id="lblUnidadeOperacional" styleClass="widthLabel">
                <h:graphicImage id="img1" value="/img/icoInterrogacao.png"  styleClass="btIco"
                title="#{uiAjuda['cadastro.uo']}" />
                #{uiLabels['geral.campoObrigatorio']}#{uiLabels['ocorrencia.uo']}
            </h:outputLabel>
            <h:selectOneMenu id="uo" value="#{cadastroController.unidadeOperacional}"
                converter="omnifaces.SelectItemsConverter"
                disabled="#{not empty cadastroController.ocorrencia.dadosOcorrencia.codigoOcorrencia}">
                <f:selectItem itemLabel="Selecione a unidade operacional" itemValue="" />
                <f:selectItems value="#{cadastroController.listaUnidadeOperacional}"
                    var="uo" itemValue="#{uo}" itemLabel="#{uo.siglaUnidadeOperativa}" />
                <a4j:ajax event="valueChange" render="ativo"
                    listener="#{cadastroController.obterListaUOAtivo}" />
            </h:selectOneMenu>
            <br />