pentaho/pentaho-kettle · error · KettleXMLException

GetPreviousRowFieldMeta.Exception.UnableToReadStepInfoFromXM…

Error message

GetPreviousRowFieldMeta.Exception.UnableToReadStepInfoFromXML

What it means

GetPreviousRowFieldMeta.readData() parses the step's <field> nodes from transformation XML. Any unexpected exception while reading the XML (malformed nodes, wrong structure, casting issues) is wrapped in a KettleXMLException with this localized message and the original exception as cause.

Solutions

Inspect the cause chain for the exact XML parsing failure and fix the .ktr XML
Re-open and re-save the step in Spoon to regenerate valid XML
Restore the transformation file from version control/backup
Align Pentaho/plugin versions between the file's origin and your runtime

Defensive patterns

Strategy: try-catch

Validate before calling

// Validate XML before load: ensure each step node has a <lookup> with <field> children
Node lookup = XMLHandler.getSubNode(stepnode, "lookup"); if (lookup == null || XMLHandler.getNodes(lookup, "field") == null) { throw new IllegalArgumentException("Corrupt GetPreviousRowField XML section"); }

Try / catch

try { meta.loadXML(stepnode, databases, metaStore); } catch (KettleXMLException e) { log.error("Step XML unreadable; restore file or re-create step", e); }

Prevention

Do not hand-edit .ktr files; edit in Spoon
Keep Pentaho runtime version aligned with file producers
Commit .ktr files and verify after merges
Back up transformations before edits

When it happens

Trigger: Loading a .ktr file whose GetPreviousRowField step XML is malformed — missing <lookup> node, corrupted <field> entries, or XML written by a different/incompatible plugin version.

Common situations: Hand-editing transformation XML and breaking the step structure; opening a transformation saved by a newer Pentaho version in an older one; truncated/corrupted .ktr files from bad checkouts or merges.

Understand the failure class

Background: "failed to unmarshal" / json.Unmarshal errors: why parsing a response into a Go struct fails and how to fix it — this error's family across 23 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/2bb447dbd17d61e0. Report an issue: GitHub.

Appendix: source

Thrown at plugins/get-previous-row-field/core/src/main/java/org/pentaho/di/trans/steps/getpreviousrowfield/GetPreviousRowFieldMeta.java:147

  }

  private void readData( Node stepnode ) throws KettleXMLException {
    try {
      int nrkeys;

      Node lookup = XMLHandler.getSubNode( stepnode, "fields" );
      nrkeys = XMLHandler.countNodes( lookup, "field" );

      allocate( nrkeys );

      for ( int i = 0; i < nrkeys; i++ ) {
        Node fnode = XMLHandler.getSubNodeByNr( lookup, "field", i );

        fieldInStream[i] = Const.NVL( XMLHandler.getTagValue( fnode, "in_stream_name" ), "" );
        fieldOutStream[i] = Const.NVL( XMLHandler.getTagValue( fnode, "out_stream_name" ), "" );
      }
    } catch ( Exception e ) {
      throw new KettleXMLException( BaseMessages.getString(
        PKG, "GetPreviousRowFieldMeta.Exception.UnableToReadStepInfoFromXML" ), e );
    }
  }

  @Override
  public void setDefault() {
    fieldInStream = null;
    fieldOutStream = null;
    schema = "";

    int nrkeys = 0;

    allocate( nrkeys );
  }

  @Override
  public String getXML() {
    StringBuffer retval = new StringBuffer( 500 );

View on GitHub (pinned to f3058517a1)