Hi Vishal,

Good find!

After a little hunting around it appears IE is very particular about how you set up pointer-events with CSS. I made one small change in the associated weighted_tree.css file to explicitly turn on pointer events and it appears to have cleared up the issue. Thanks for letting me know.

svg.vz-weighted_tree-viz {
fill:none;
font-family:Roboto;
pointer-events:visible;
}