pentaho/pentaho-kettle · error · KettleStepException

Error creating value meta for output field

Error message

Error creating value meta for output field '{fieldName}'

What it means

MetaInjectMeta.getFields() builds the step's output row metadata from the configured sourceOutputFields. field.createValueMeta() throws KettlePluginException when the field's data type or conversion metadata cannot be instantiated; this is wrapped in a KettleStepException naming the offending field.

Solutions

  1. Check the fieldName in the message and fix its declared data type in the Meta Inject mapping grid.
  2. Ensure the source step still produces that field with a supported type.
  3. Verify all required Kettle plugins (value type providers) are installed.
  4. Re-select the source field in the step dialog so type metadata is regenerated.

Example fix

// before: mapping with stale/invalid type
field.setType(-1);
// after: explicit valid type
field.setType(ValueMetaInterface.TYPE_STRING);
Defensive patterns

Strategy: validation

Validate before calling

// Validate each output field's type before calling getFields
for (MetaInjectOutputField f : sourceOutputFields) {
  if (f.getType() < 0 || f.getType() >= ValueMetaInterface.typeCodes.length) {
    throw new IllegalArgumentException("Invalid type for field " + f.getName());
  }
}

Type guard

boolean hasValidTypes(List<MetaInjectOutputField> fields) {
  return fields.stream().allMatch(f -> f.getType() != -1);
}

Try / catch

try {
  meta.getFields(bowl, rowMeta, origin, info, nextStep, space, repository, metaStore);
} catch (KettleStepException e) {
  logError("Bad output field metadata: " + e.getMessage(), e);
}

Prevention

When it happens

Trigger: getFields() iterating sourceOutputFields where a MetaInjectOutputField has an invalid/unknown type, or a plugin providing the required value meta is missing, so field.createValueMeta() throws.

Common situations: A mapping references a source field whose type was changed or removed upstream; missing value-type plugin jars; transformation copied between environments with different plugin sets.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/d38e13f766dd5dcf. Report an issue: GitHub.

Appendix: source

Thrown at plugins/meta-inject/impl/src/main/java/org/pentaho/di/trans/steps/metainject/MetaInjectMeta.java:380

        rep.saveStepAttribute( id_transformation, id_step, i, MAPPING_SOURCE_STEP, source.getStepname() );
        rep.saveStepAttribute( id_transformation, id_step, i, MAPPING_SOURCE_FIELD, source.getField() );
      }
    } catch ( Exception e ) {
      throw new KettleException( "Unable to save step information to the repository for id_step=" + id_step, e );
    }
  }

  @Override
  public void getFields( Bowl bowl, RowMetaInterface rowMeta, String origin, RowMetaInterface[] info, StepMeta nextStep,
                         VariableSpace space, Repository repository, IMetaStore metaStore ) throws KettleStepException {

    rowMeta.clear(); // No defined output is expected from this step.
    if ( !Utils.isEmpty( sourceStepName ) ) {
      for ( MetaInjectOutputField field : sourceOutputFields ) {
        try {
          rowMeta.addValueMeta( field.createValueMeta() );
        } catch ( KettlePluginException e ) {
          throw new KettleStepException( "Error creating value meta for output field '" + field.getName() + "'", e );
        }
      }
    }
  }

  @Override
  public StepInterface getStep( StepMeta stepMeta, StepDataInterface stepDataInterface, int cnr, TransMeta tr,
                                Trans trans ) {
    return new MetaInject( stepMeta, stepDataInterface, cnr, tr, trans );
  }

  @Override
  public StepDataInterface getStepData() {
    return new MetaInjectData();
  }

  public Map<TargetStepAttribute, SourceStepField> getTargetSourceMapping() {
    return targetSourceMapping;

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