pentaho/pentaho-kettle · error · RuntimeException

Unknown XML event: [event]

Error message

Unknown XML event: [event]

What it means

Identical RuntimeException from XMLFormatter.format()'s default switch case; the recorded message contains the event value already substituted ('[event]'), meaning the formatter hit an XML stream event type it does not know how to render.

Solutions

1. Identify the event constant from the message value and handle it explicitly in the switch
2. Skip benign events (comment, DTD, processing instruction) instead of throwing
3. Pre-process the XML to remove non-content nodes
4. Configure the XMLInputFactory to coalesce text and expand entity references
5. Catch RuntimeException around format() and fall back to returning the input unformatted

Example fix

// before
String out = XMLFormatter.format( xml );
// after
String out;
try {
  out = XMLFormatter.format( xml );
} catch ( RuntimeException e ) {
  log.logMinimal( "XML formatting failed, using original: " + e.getMessage() );
  out = xml;
}

// Same pre-check as 576
boolean risky = xml.contains( "<!DOCTYPE" ) || xml.contains( "<?" ) || xml.contains( "<!--" );

try {
  result = XMLFormatter.format( xml );
} catch ( RuntimeException e ) {
  if ( e.getMessage().startsWith( "Unknown XML event:" ) ) {
    log.logMinimal( "Skipping formatting: " + e.getMessage() );
    result = xml;
  } else {
    throw e;
  }
}

When it happens

Trigger: Same as 576: the StaX cursor returns an event constant not covered by the implemented cases (e.g. COMMENT=5, DTD=11, PROCESSING_INSTRUCTION=3) while formatting.

Common situations: Same as 576: documents with DOCTYPE, comments, processing instructions, or entity references; differences between StaX implementations (Woodstox vs JDK default).

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Unknown XML event:
• AnalyticQueryMeta.Exception.UnableToLoadStepInfoFromXML
• Error_0001
• ERROR_0001
• Error loading transformation executor details from XML

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/c705fb5e986ad822. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/pentaho/di/core/xml/XMLFormatter.java:143

            cdata.append( rd.getText() );
            wasSomething = true;
            break;
          case XMLStreamConstants.COMMENT:
            if ( !whitespacesOnly( str ) ) {
              wr.writeCharacters( str.toString() );
            } else if ( wasSomething ) {
              wr.writeCharacters( "\n" + prefix );
            }
            str.setLength( 0 );
            wr.writeComment( rd.getText() );
            wasSomething = true;
            break;
          case XMLStreamConstants.END_DOCUMENT:
            wr.writeCharacters( "\n" );
            wr.writeEndDocument();
            break;
          default:
            throw new RuntimeException( "Unknown XML event: " + event );
        }
      }

      wr.flush();

      return result.toString();
    } catch ( XMLStreamException ex ) {
      throw new RuntimeException( ex );
    } finally {
      try {
        if ( wr != null ) {
          wr.close();
        }
      } catch ( Exception ex ) {
      }
      try {
        if ( rd != null ) {
          rd.close();

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