Plato software error

I am getting this error while using plato for one of my project to find maintainability index for angular.js application

plato -r -d report "angular" angular-master C:\Users\pritesh\AppData\Roaming\npm\node_modules\plato\lib\util.js:15 var lastSlash = files[0].lastIndexOf(path.sep); ^

TypeError: Cannot read property 'lastIndexOf' of undefined at Object.exports.findCommonBase (C:\Users\pritesh\AppData\Roaming\npm\node_modules\plato\lib\util.js:15:27) at Object.exports.inspect (C:\Users\pritesh\AppData\Roaming\npm\node_modules\plato\lib\plato.js:86:29) at Object.exports.exec (C:\Users\pritesh\AppData\Roaming\npm\node_modules\plato\lib\cli.js:53:9) at Object. (C:\Users\pritesh\AppData\Roaming\npm\node_modules\plato\bin\plato:19:5) at Module._compile (module.js:410:26) at Object.Module._extensions..js (module.js:417:10) at Module.load (module.js:344:32) at Function.Module._load (module.js:301:12) at Function.Module.runMain (module.js:442:10) at startup (node.js:136:18)