I had the same problem, but I noticed those files that error out are files with Forms. I even tried it with the sample generator and got the same error. Here is how to replicate it: 1. Run the Sample class. 2. Select option 0 - AcroFormCreationSample 3. Create the form file and quit the application. 4. Copy the output file into the samples folder 5. Run the Sample class again. 6. Select option 27 - PageManagementSample 7. Select option 5 - Document Merge 8. You will now find your sample file is the...