HTML5 'Downloading Failed' error message

I’ve packaged for HTML5 and uploaded to a free web hosting service ( for testing, but I’m getting this error when I try to view the page

Downloading failed:
HTTP error 404 Not Found on file UE4Game-HTML5-Shipping.asm.js
Your browser does not support WebAssembly (and there is no asm.js fallback deployed of this page). Please try with latest 64-bit browser.
Current user agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0
TypeError: Module.asm is not a function

Browser is 64-bit version and I’ve tried on Chrome too and get the same thing… any ideas?

Your browser does not support WebAssembly