Where should be .unity3D file?

Hi Experts,
I recently developed a game in Unity3D and want to publish this on Facebook. I purchased a normal domain www.xyz.com and create a folder in it named “demo”, I gave this address in Facebook development where required as https://xyz.com/demo/client.unity3d
But whenever I go to my application page it shows an error “Failed to download data file”?

What is my mistake?? Please help…

Just try direct link from browser. For example https://xyz.com/demo/client.html
I’ve got the same problem. Direct link is ok,but from FB it shows “Failed to download data file” I don’t think so that there is a problem with publicity. If direct link failed just control the name of unity3d file in html file.