Recently we copied our _admin folder and KDBs from other environment to our stag

Eduardo, thanks for your response. That's actually exactly what I did. I did it because without doing that my internal filename was null, which in turn caused my code to not work. How can I tell Appian to go ahead and set its internal filename and id and then return them to me? I figured out what I could from the public Java API, but for lack of more thorough knowledge on Appian's internal workings this is my code looks:

          String mergeResultDocName = "Merge_Result_Doc";
                    String mergeResultDocExtension = "pdf";
                    Document mergeResultDoc = new Document(folder, mergeResultDocName, mergeResultDocExtension);
                    mergeResultDoc.setSize(1);
                    mergeResultDoc.setFileSystemId(ContentConstants.ALLOCATE_FSID);
                    mergeResultDoc.setInternalFilename("C:\\\\appian\\\\_admin\\\\accdocs3\\\\2050\\\\" + mergeResultDocName + ".pdf");
                    mergeResultDoc.setState(ContentConstants.STATE_ACTIVE_PUBLISHED);
                    Long docId = cs.create(mergeResultDoc, ContentConstants.UNIQUE_FOR_TYPE);
                    mergeResultDoc.setId(docId);
                    
                    try {
                              File destinationFile = new File(mergeResultDoc.getInternalFilename());
                              FileOutputStream fos = new FileOutputStream(destinationFile, true);
                              Rectangle size = RectangleFinder.getRectangleSize(inputs);
                                        
                              PdfVeryDenseMergeTool tool = new PdfVeryDenseMergeTool(size, paddingSize, paddingSize, contentGapSize);
                              tool.merge(fos, inputs);
                    
                    } catch (Exception e) {
                              System.out.println("*******There has been an error creating the fileoutput stream and running the merge tool.******");
                              System.out.println(e);
                    }

Eduardo, thanks for your response. That's actually exactly what I did. I did it because without doing that my internal filename was null, which in turn caused my code to not work. How can I tell Appian to go ahead and set its internal filename and id and then return them to me? I figured out what I could from the public Java API, but for lack of more thorough knowledge on Appian's internal workings this is my code looks:

          String mergeResultDocName = "Merge_Result_Doc";
                    String mergeResultDocExtension = "pdf";
                    Document mergeResultDoc = new Document(folder, mergeResultDocName, mergeResultDocExtension);
                    mergeResultDoc.setSize(1);
                    mergeResultDoc.setFileSystemId(ContentConstants.ALLOCATE_FSID);
                    mergeResultDoc.setInternalFilename("C:\\\\appian\\\\_admin\\\\accdocs3\\\\2050\\\\" + mergeResultDocName + ".pdf");
                    mergeResultDoc.setState(ContentConstants.STATE_ACTIVE_PUBLISHED);
                    Long docId = cs.create(mergeResultDoc, ContentConstants.UNIQUE_FOR_TYPE);
                    mergeResultDoc.setId(docId);
                    
                    try {
                              File destinationFile = new File(mergeResultDoc.getInternalFilename());
                              FileOutputStream fos = new FileOutputStream(destinationFile, true);
                              Rectangle size = RectangleFinder.getRectangleSize(inputs);
                                        
                              PdfVeryDenseMergeTool tool = new PdfVeryDenseMergeTool(size, paddingSize, paddingSize, contentGapSize);
                              tool.merge(fos, inputs);
                    
                    } catch (Exception e) {
                              System.out.println("*******There has been an error creating the fileoutput stream and running the merge tool.******");
                              System.out.println(e);
                    }