Missing Command Error in Windows Phone 8.1

[gogodigimo]

I have a simple call to window.canvas2ImagePlugin.saveImageDataToLibrary as seen below:

        window.canvas2ImagePlugin.saveImageDataToLibrary(
            function (msg) {
                $scope.ShareThisPicture(msg);
            },
            function (err) {
                $scope.SimpleAlert("Error", err);
            },
            document.getElementById('myCanvas')
        );

However, when I call the function on an Window Phone 8.1 emulator, I get an error "Missing Command Error" thrown. Any idea what might be causing this?