Mp4 Problems: video doesn't play

I’m using the free version of and want to show videos on my page. I could upload mp4 files but couldn’t play the videos. There is the error “system information missing”. I’m new in working with Omeka so sorry for the maybe simple question.
It would be great if anyone could help me!
Thank you!

Hi there. questions should be sent via the contact form on that site

Hello! Oh, ok. Thank you!