I have download 1.8.23 version but
console.log(go.version); // return 1.6.22
I have try all three functions Diagram.makeImage, makeImageData and Diagram.makeSvg
but result i same.
Mian div element has widht 100% or auto to fit in every screen size this is why both HTML images has different size but i have also try with fixed width but no success.
All other machines in my office export image with black area but
my system exporting image without any problem
I have try different browsers on other machines but same result
I have also create a code example for debugging and sent to gojs.
Thanks