2320177 - "HTTP response code 504" error when trying to view 'Preview Results' within PRD

When trying to view the contents of the 'Preview Results' tab when configuring a custom report withn PRD, the following error is generated -

org.eclipse.birt.report.engine.api.EngineException: Error happened while running the report.
 at org.eclipse.birt.report.engine.api.impl.DatasetPreviewTask.doRun(DatasetPreviewTask.java:318)
 at org.eclipse.birt.report.engine.api.impl.DatasetPreviewTask.runDataset(DatasetPreviewTask.java:280)
 at org.eclipse.birt.report.engine.api.impl.DatasetPreviewTask.execute(DatasetPreviewTask.java:91)
 at org.eclipse.birt.report.designer.data.ui.dataset.DataSetPreviewer.preview(DataSetPreviewer.java:68)
 at org.eclipse.birt.report.designer.data.ui.dataset.ResultSetPreviewPage$5.run(ResultSetPreviewPage.java:366)
 at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:122)
Caused by: org.eclipse.birt.report.data.adapter.api.AdapterException: An exception occurred during processing. Please see the following message for details:
Failed to prepare the query execution for the data set: Data Set
Cannot get the result set metadata.
    org.eclipse.birt.report.data.oda.jdbc.JDBCException: SQL statement does not return a ResultSet object.
SQL error #1:java.sql.SQLException: java.io.IOException: Server returned HTTP response code: 504 for URL: https://<customer instance>-stage.plateau.com/vjdbc/vjdbc

SuccessFactors Learning Management System (LMS) - All Supported Versions

Plateau Report Designer

HTTP response code 504; PRD; VJDBC; Preview Results; , KBA , LOD-SF-LMS-PRD , VJDBC Setup or Connection Issues , LOD-SF-LMS-REP , Reporting Data , How To