Solr and schemaless

Question

I'm using Cloudera 5.4 with Solr 4.10.2 and I would like to activate the schemaless.

I've edited the solrconf.xml with

<schemaFactory class="ManagedIndexSchemaFactory">
    <bool name="mutable">true</bool>
    <str name="managedSchemaResourceName">managed-schema</str>
</schemaFactory>

I don't know if I need something else for this version. I have read the Solr documentation (https://docs.lucidworks.com/display/solr/Managed+Schema+Definition+in+SolrConfig)

When I try to index an document, I get an exception:

Exception in thread "main" org.apache.solr.client.solrj.impl.CloudSolrServer$RouteException: ERROR: [doc=5.417393032179468E7] unknown field 'campo1'

I have seen that there's an schema.xml.bak how the documentation says.

Do I need to do something else?