Please review the following issues that occurred problem

Hi!

I recently registered on codecanyon for wish to put my mobile source code app online for sale.
The problem is that every time I receive the same message and i can not understand it in the field “Optional Video Preview”.

The error message that appears:

“”" Please review the following issues that occurred

Optional Live Preview A zip file was uploaded and no index.html was found (and yes this is case sensitive).
Optional Video Preview ‘index.html’ is not a valid video preview. “”"

Can you help me please
thanks