Storyline first slide video problem

Hi Yunus, 

Thanks so much for reaching out. I found a related discussion where they are encountering a similar issue. What you are experiencing is related to the browser permissions when using Chrome.

Here's a blurb from the article I linked for a quick look:

Audio and video content on other slides in your course should play as expected. However, if your slides are set to advance automatically without any interaction, media might not work since learners haven't given their browsers permission to play it.

I hope this helps! 🎉