Hi, I recently upgraded from PowerDirector 12 to 13 and had the same exact issue with only audio and no video after producing a MP4 video using the H.265 HEVC settings. I switched to the H.264 AVC and was able to get both audio and video in my Mp4 file. So, I thank you for this advice! But, I would like to know why the H.265 HEVC did not work. Could you please explain why this didn't work? Thanks!
H.265 HEVC is a new encoding method, not very many players can decode that format. H.264 has been around of a long time now, most players can play H.264 encoded videos.