Hi Michael,

In the latest v4 Beta, Feb-26-2019, I've come across another "scroll wheel" bug when using nodeeditor, similar to the previously reported one, which you seem
to have corrected from the previous Beta. The correction is appreciated. The bug also occurs in the previous Beta.

There are two manifestations. The first is a scroll wheel "hole" in the nodeeditor screen, near the upper center of the MoI screen, down maybe 2 inches.
The nodeeditor screen is partially overlapping the MoI screen. (It is not too hard to find, but some scroll/zooming of the depth of the ne screen may be needed.)
Normally, mouse wheel action in the nodeeditor screen causes it to scroll and zoom. In the "hole" area, the MoI screen scroll/zooms instead.
Second, nodes dragged and dropped into this "hole" area fly off, and out of view, to the upper left corner of the nodeeditor screen.
Scroll/zooming the ne screen permits the nodes to be dragged back into the ne screen box.

So the easiest way to find it is some trial and error ne zooming, and then scroll wheel action on the upper center area of the ne screen.
When MoI scroll/zooms instead of ne, the "hole" is found.

- Brian