I’m using Windows 10. I have an Impress presentation with a video. It plays perfectly in my Dell, but when I transferred it to my Sony laptop and advance to the video slide it plays the sound with no picture. If I start the slideshow from that slide it plays perfectly. The video is in MPEG format.
EDIT by ebot, Answer postponed; 20191221-10.12 MEZ:
Perhaps it’s a driver problem. I’ve managed a rather rubbish solution. Insert the video using the Insert menu, mute the sound. Insert it again (I used the Tools - Media Player) I have the visuals and sound in sync. Video is slightly jerky, but it’s an old one transferred from video tape so not so critical. That’s the best I can do using my limited knowledge. My son is coming over later, he may have a better idea.