According to the accepted answer of the following question: FacesException: DataModel must implement org.primefaces.model.SelectableDataModel when selection is enabled its required to implement SelectableDataModel or add the rowKey attribute to the dataTable to avoid that exception. Anyway I just added the rowKey attribute as you can see and the error still happening, hope someone can tell me why.
This is my dataTable:
<p:dataTable var="item" rowKey="#{item.id}" style="margin-top:5px" emptyMessage="Nenhum registro encontrado"
value="#{controller.entidade.ecfs}" rows="10" selectionMode="single"
paginator="#{ecfController.showPaginator()}" paginatorPosition="bottom">
<p:column headerText="Nº Série">
<p:outputLabel value="#{item.numeroSerie}"/>
</p:column>
<p:column headerText="Modulo">
<p:outputLabel value="#{item.modulo}"/>
</p:column>
<p:column headerText="Modelo">
<p:outputLabel value="#{item.modelo}"/>
</p:column>
<p:column headerText="GT Inicial">
<p:outputLabel value="#{item.gtInicial}"/>
</p:column>
</p:dataTable>