Running unity with NodeJS

I'm using NodeJS with Express and trying to run a Unity html file on my site.

Basically what I'm trying to do is to get a Unity html file I have to play on my NodeJS site. The files are WebPlayer.html and WebPlayer.unity3d. If I open up the local copy of WebPlayer.html in my browser, the game plays fine. However, if I try to run the game through my site, I get the message Failed to download data file. I've looked this up, and have seen people having the same issues as me, but couldn't find too many helpful suggestions from people using node. Any help would be appreciated. Thanks!

Running the local copy in my browser (unity is loading the game and is working fine).
file:///Users/thomasbaldwin/Desktop/WebPlayer.html

Running the WebPlayer.html file on my local server.
http://localhost:3000/account/game/