I have used Impress for many years. Suddenly, video clips are flickering. It happens very fast, but it looks like the flicker is showing the thumbnail of the video. If i link the video, then it shows the gray box with the question mark. If I insert the video, it shows the video thumbnail frame.
Libreoffice version: 18.104.22.168
OS: Ubuntu 17.04
Any help would be greatly appreciated!