problem of associating a data source associated with Word mail merge from a java application (OLE communication)

Question

I'm working on a java application that interacts with Word through an OLE library (org.eclipse.swt.ole.win32) to merge documents (mail merge). the java method which makes it possible to merge has been working for several years without any particular problem.

but recently the data source can no longer be associated with the merge document. This problem is random (on some workstations it works and on others it doesn't, yet same system configuration) I have no explicit error reported on the java side Here is the method that communicates with Word:

  public void mergeDocument(File model, File source) throws Exception {
    OleAutomation autoMailMerge = null;
    LOGGER.log(new Status(IStatus.INFO, pluginID, "Merge d un document"));
    LOGGER.log(new Status(IStatus.INFO, pluginID, "fichier modele: " + model.getCanonicalPath()));
    LOGGER.log(new Status(IStatus.INFO, pluginID, "fichier source: " + source.getPath()));
    openDocumentReadOnly(model);

    autoMailMerge = OLEHelper.getAutomationProperty(autoDocument, "MailMerge");
    if ((source != null) && (source.exists()) && (!source.isDirectory())) {
      OLEHelper.invoke(autoMailMerge, "OpenDataSource", source.getPath());
    } else {
      throw new MSWordOleInterfaceException(MSWordOleInterfaceCst.MSG_ERROR_EMPTY_SOURCE_PATH
          + ((source == null) ? "null" : source.getPath()));
    }
    OLEHelper.invoke(autoMailMerge, "Execute");

    OleAutomation autoDocumentMerged = getActiveDocument();
    closeDocument(autoDocument);
    activateDocument(autoDocumentMerged);
    autoDocument = autoDocumentMerged;
    autoMailMerge.dispose();
  }

• Merging by hand from Word (associating the data source and merging) works on workstations where the java application does not work.

• thanks to the OLE command I validated that it is the data source which is not passed (on a workstation which works I have a return with the name of the source, on one or it does not work the return is empty)

    LOGGER.log(new Status(IStatus.INFO, pluginID, "data source name: "
        + OLEHelper.getVariantProperty(autoDataSource, "Name").getString()));

-a temporary solution has been found, by deleting the registry key related to office:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Word\DocumentTemplateCache

but this is only a temporary solution, the problem comes back.