MethodNotFound Exception - Chart.TakeChartshot()

Hi Automaters,

I'm looking to add the ability to take a chart shot programmatically from an indicator I'm building. The section of code looks as follows:

if (Chart.IsActive)
{
    var chartShot = Chart.TakeChartshot();
    File.WriteAllBytes(@"D:\Documents\cTrader\Chartshots\chartshot_tmp.png", chartShot);
}

When this is executed, I get the following exception: 

MissingMethodException: Method not found: 'Byte[] cAlgo.API.Chart.TakeChartshot()'

The method is found and suggested when writing that line of code and the indicator compiles fine.  The chart is active, as required by the method.

I have tested this same code in a cTrader robot, however the method TakeChartshot() is not recognised at all (unlike in the indicator version).

Has anyone else come across this issue or know of any work arounds?

Thanks in advance.