WebGL: Incorrect Header Check

I always get the following error:

An error occured running the Unity content on this page. See your browser's JavaScript console for more info. The error was:uncaught exception: incorrect header check

What I've tried to solve this issue:

1- Deleting .htaccess file

2- Changing index.html file like following(added gz to data js and mem to end of the words)

 var Module = {
     TOTAL_MEMORY: 268435456,
     errorhandler: null,            // arguments: err, url, line. This function must return 'true' if the error is handled, otherwise 'false'
     compatibilitycheck: null,
     dataUrl: "Release/Webgl.datagz",
     codeUrl: "Release/Webgl.jsgz",
     memUrl: "Release/Webgl.memgz",
   };

but problem still exists. I've search lots of documents about this but couldn't find anything useful. Any ideas ?