Highcharts Phantomjs Export - TypeError: 'undefined' is not an object

Generating a png file from config-

phantomjs-1.8.1/bin/phantomjs highcharts-convert.js -infile config.json  -outfile out1.png -width 300 -scale 2.5 -constr Chart -callback callback.js

Error-

	TypeError: 'undefined' is not an object (evaluating 'svgElem.getAttribute')
	phantomjs://webpage.evaluate():20
	phantomjs://webpage.evaluate():23
	phantomjs://webpage.evaluate():23
	TypeError: 'null' is not an object (evaluating 'svg.width')
	highcharts-convert.js:89
	highcharts-convert.js:322
	:/modules/webpage.js:277

view raw gistfile1.js hosted with ❤ by GitHub

Things to check-
1. The following 3 files should be there in same folder or you have to set the paths to these here-
var config = {
                /* define locations of mandatory javascript files */
                HIGHCHARTS: 'highstock.js',
                HIGHCHARTS_MORE: 'highcharts-more',
                JQUERY: 'jquery-1.8.2.min.js'
        },

2. The 'infile' parameter should have an extension of .json, because that is what it uses to decide between svg input and a configuration json.