An incredibly unique ERROR: Line: 56: TypeError: undefined is not an object (evaluating 'i.data.properties[a].toNumber') because of course - error-handling

Question

This is my code, written on code.org, link here. the error is in the last 'if' statement. What I don't understand is how this is failing when another program of mine, written the exact same way (I copy-pasted it into this program) works!
I just don't know what could possibly be breaking this, and the error message is just some obscure thing that I can't find anywhere else in the same context! Whyyyyy!?
var R; var G; var B;
createCanvas('pattern');
setActiveCanvas('pattern');
var data = getImageData(0, 0, 320, 450);
//R = x * 0.796875;
//G = Math.ceil(y * 0.02222222) * 25.5;
//B = (y * 0.3333333) * 17 - Math.floor(y * 0.02222222) * 255;
for (var x = 0; x < 320; x+=2) {
for (var y = 0; y < 450; y+=2) {
setRGB(data, x, y, x * 0.7968, Math.ceil(y * 0.0222) * 25.5, (y * 5.6661) - Math.floor(y * 0.0222) * 255);
}
}
putImageData(data, 0, 0);
{
createCanvas('canvas');
createCanvas('buffer');
hideElement('buffer');
setActiveCanvas('canvas');
setStrokeWidth(1);
setStrokeColor(rgb(255,255,255,255));
setFillColor(rgb(255,255,255,255));
rect(0, 0, 320, 450);
var bufferData = getImageData(0, 0, 320, 450);
var imgData = getImageData(0, 0, 320, 450);
setStrokeColor('black');
setFillColor('black');
var circleX;
var circleY;
var redValue = getRed(bufferData, 50, 50);
}
for (var i = 0; i < 200; i++) {
setActiveCanvas('buffer');
setStrokeColor('white');
setFillColor('white');
rect(0, 0, 320, 450);
setStrokeColor('black');
setFillColor('black');
circleX = 160 + Math.cos(i * 0.0314) * 40;
circleY = 225 + Math.sin(i * 0.0314) * 40;
circle(circleX, circleY, 50);
imgData = getImageData(0, 0, 320, 450);
setStrokeColor('white');
setFillColor('white');
rect(0, 0, 320, 450);
bufferData = getImageData(circleX - 50, circleY - 50, 100, 100);
for (var drawX = circleX - 50; drawX < circleX + 49; drawX++) {
for (var drawY = circleY - 50; drawY < circleY + 49; drawY++) {
if (getRed(imgData, drawX, drawY)==0) {
setRGB(bufferData, drawX, drawY, 0,0,0,0);
}
}
}
setActiveCanvas('canvas');
putImageData(bufferData, 0, 0);
}