What is this DalekJS error when I try to run a test via PhantomJS?

Every time I try to run a test using PhantomJS, Dalek gives me this error. However using GoogleChrome the test runs properly.

Running tests

/Users/user/node_modules/dalekjs/node_modules/dalek-browser-phantomjs/index.js:273

this.spawned.kill('SIGTERM');

            ^



TypeError: Cannot read property 'kill' of null

  at Object.PhantomJSDriver.kill (/Users/user/node_modules/dalekjs/node_modules/dalek-browser-phantomjs/index.js:273:17)

  at EventEmitter.emit (/Users/user/node_modules/dalekjs/node_modules/eventemitter2/lib/eventemitter2.js:312:17)

  at Object.Dalek._shutdown (/Users/user/node_modules/dalekjs/lib/dalek.js:346:24)

  at emitOne (events.js:77:13)

  at process.emit (events.js:169:7)

  at process._fatalException (node.js:211:26)

What could the problem be?

Please note that I am using OS X 10.10.5 and I am beginner at Dalek and JS test automation. Thanks!