Thanks for your inquiry. Please note we maintain a single code base of our API. All fixes and enhancements are made in latest version, so we can not provide you hotfix for older version. It is always recommended to use latest version.
Furthermore, you may try to resize your PDF document
before concatenation. However if it does not work then please share your sample code and documents here we will test the scenario at our end and will guide you accordingly.
int page_cnt1 = new int[pdfDocument.Pages.Count];
for (int i = 0; i <
page_cnt1[i] = i + 1;
PdfFileEditor pfe = new PdfFileEditor();
Please feel free to contact us for any further assistance.