Why is the Video tag not working?

Question

HTML

The working site has:

<video class="trying__hidden" id="video"    preload="auto" loop> </video>

Video is not shown on the development server. On the working - is shown.
The only difference is that on the apache production server, on the nginx development server. PHP both there and there 5.6.
What to look for, what else can be checked?

Answer 1

It doesn't matter what server you have. see file paths and work with video format extensions. <video></video>

Answer 2

Look in the console for a 404