After you load video files, this program will automatically calculate the corresponding output file size and show it on the capacity bar at the bottom of the main window. And you should select DVD/BD type by it. Please be sure that the color lump on the capacity bar is only in blue. If not, you cannot finish the creating with all the files you loaded.
This FAQ is about: Blu-ray Creator, Blu-ray Creator for Mac, DVD Creator, DVD Creator for Mac, Frequently Asked Questions, Total Media Converter Ultimate, Video Converter Ultimate