For reference, the error message generated was:   
/home/symbly/www/d20-api-server/node_modules/firebase/lib/firebase-node.js:1 orts, require, module, __filename, __dirname) { function g(a){throw a;}var j=v 
                                                                    ^
 ReferenceError: version is not defined
     at Object.WeightedDice.CheckInstall (evalmachine.<anonymous>:1473:34) 
    at Sandbox.<anonymous> (evalmachine.<anonymous>:1549:15) 
    at eval (  /home/symbly/www/d20-api-server/node_modules/firebase/lib/firebase-node.js:1 orts, require, module, __filename, __dirname) { function g(a){throw a;}var j=v