Title field input not appearing when creating content type by module
the error is obviously because you use a wrong base
change it to 'ct_conversacion'
see https://api.drupal.org/api/drupal/modules%21node%21node.module/function/node_type_save/7
base: A string that indicates the base string for hook functions. For example, 'node_content' is the value used by the UI when creating a new node type.