Steps to reproduce:

1. Download the cache server from our site (http://unity3d.com/unity/collaboration/)
2. Extract the downloaded package
3. Navigate to one of the 'builds' folder
4. Notice that it uses a very old version of node.js (0.6.6 to be exact)

Workaround: Download newer version of node.js (currently newest is 4.2.4) from their official page (https://nodejs.org/en/download/) and replace it with the one used by cache server (also, the obsolete method "path.existsSync" should be replace with "fs.existsSync" in the scripts)

There is also a 64-bit version, which we should use to prevent out of memory problems.