Fatal error when trying to run a HTML5 build

I have created the project as HTML5 version game (Build game - HTML5 option). But when I try to run it (when I open the index.html file), it only shows the error window: FATAL ERROR, undefined, undefined:undefined. I have tried it with two completely different projects and get the same error. I have opened ti with different web browsers but it is still the same.

When I build it as a windows game it works perfectly. 

Has anyone had similar problems? Any idea what can be wrong?

You can use things like this to test it: https://chrome.google.com/webstore/detail/web-server-for-chr...