Video Not Playing

Hello.
Can anyone please help. I have problems getting video to play. When i embed or insert sometimes it would just start playing and sometimes it will not. Am at a loss what the problem could be.

I had removed filtering yet no solution

Hi, but where you added this movie code ?

Sometime you have to use plugin to show video inside article(s).
For example check: Allvideos - joomlaworks.gr

Thanks for the quick reply.
I was adding it through k2 items article manager.

See attached file.

Try to add video code inside (like from youtube) - not by uploading movie for those which you have problems.
K2 is not our software - so we can not help in this case if something not working well.

p.s.
About why sometimes it works and sometimes not - there could be many reasons also hosting transfer or browser coders problems.