Embedded Video created in MS PowerPoint not working in Impress

I have Impress and the Mega K-Lite Codec package installed.

My embedded video (MP4) always plays the sound, but not always the video after a shut down and restart of the laptop.

I have set the default media player to VLC.

Is there a better default to play my videos?

As I use LO for our club, a speaker may come with an embedded video in MS PowerPoint format and I need to be able to play it on the day.

Otherwise I am happy with LO.

Russell