Please make sure the newest version of Adobe Acrobat Reader is installed. Please only use programms to open the file that are made to view PDFs and not to edit them. Our PDFs are protected against changes. If an editing programm should be used it could be that it won't open or that certain logos e.g. event name, date, or seat number won't print. If you are using the newest version of Adobe and there still are problems, contact customer service.