Why Popup Editor has vertical scrolling?

I have set WeightPx and HeightPx to be blank which is default -1 means will fit to content.

But the result always has vertical scroll this is irritating. Howto fix this?

I don't want to hard code the pixels if possible.


Can't answer why it's showing without checking the CSS of the popup.

But to fix, you might be able to fix it adding CSS to the popup page:

body {
  overflow-y: hidden;