ORA-00932 on subquery join from subquery join The only guess I have is that perhaps the size of the subquery is considered a CLOB?  I have no null values for the fields selected AFAIK.

SELECT DISTINCT 
    kbq_ent.qid AS kbq_ent_qid,
    kbq_ent.category AS kbq_ent_category,
    kbq_ent.consequence AS kbq_ent_consequence,
    kbq_ent.diagnosis AS kbq_ent_diagnosis,
    kbq_ent.last_service_modify_datetime AS kbq_ent_last_servic_1,
    kbq_ent.patchable AS kbq_ent_patchable,
    kbq_ent.pci_flag AS kbq_ent_pci_flag,
    kbq_ent.published_datetime AS kbq_ent_published_d_2,
    kbq_ent.severity_level AS kbq_ent_severity_le_3,
    kbq_ent.solution AS kbq_ent_solution,
    kbq_ent.title AS kbq_ent_title,
    kbq_ent.vuln_type AS kbq_ent_vuln_type,
    kbq_ent.discovery_remote AS kbq_ent_discovery_r_4,
    kbq_ent.cvss_base AS kbq_ent_cvss_base,
    kbq_ent.cvss_temporal AS kbq_ent_cvss_tempor_5,
    kbq_ent.last_customization_user_login AS kbq_ent_last_custom_6,kbq_ent.last_customization_datetime AS kbq_ent_last_custom_7 
FROM kbq_ent JOIN (SELECT vuln_eid AS vuln_eid, qid AS qid, anon_2.rel_eid AS anon_2_rel_eid 
FROM (
        SELECT entity_vuln.entity_id AS vuln_eid,
            entity_vuln.qid AS qid 
        FROM entity_vuln
    ) JOIN (
        SELECT entity_responsible_org.entity_id AS rel_eid
        FROM entity_responsible_org 
        WHERE entity_responsible_org.org_id = :org_id_1
    ) anon_2 ON vuln_eid = anon_2.rel_eid) anon_1 ON kbq_ent.qid = anon_1.qid


kbq_ent.solution AS kbq_ent_solution is a CLOB.
LOB Rules and Restrictions


  ...
  
  
  You cannot specify LOB columns in the ORDER BY clause of a query, the
  GROUP BY clause of a query, or an aggregate function.
  You cannot specify a LOB column in a SELECT... DISTINCT or SELECT...
  UNIQUE statement or in a join. However, you can specify a LOB
  attribute of an object type column in a SELECT... DISTINCT statement,
  a query that uses the UNION, or a MINUS set operator if the object
  type of the column has a MAP or ORDER function defined on it.
  
  
  ...