Broken widgets in 4.9.

I noticed my functional UMG code in 4.8 is now causing me grief in 4.9, specifically widgets I’d expect to be visible don’t show up.

As others are also reporting problems, do anyone know the exact problems that come from the changes, and if possible how to deal with them? The question is quite vague I guess but if there’s a lot of issues with widgets in 4.9 it might be a good idea to keep the issues, workarounds and less obvious changes in UMG workflow in one thread.

The Jamsh mentioned this in the 4.9 release thread for instance:
‘Lot’s of Widget stuff seems to be broken in 4.9, and for some breakages there are no workarounds. A lot of this I suspect is due to the new Cached Widget stuff / Invalidation stuff.’

Let’s see if this goes anywhere… thanks for any input!

The invalidation panel is not involved. The Jamsh’s problems stemmed from a change to the Canvas widget. Which no longer Paints (Which includes Ticks) any children that are outside the bounds of the widget. We’re eliminating performance problems from Slate and painting/ticking widgets you can’t see is a bad one.

The only difference I noticed was I had an image as the background of a menu, and when I brought it into 4.9 that image was on to of the rest of my stuff in the widget. So I had to set the z order for that image to -1 so it went behind everything. But I am doing a few things with widgets right now, so if I have any issues I will report them.

Ordering issues were fixed in the canvas, you may have been getting the ‘correct’ order for the wrong reasons previously. You don’t need to change ZOrder, you can just adjust the order of the components in the canvas. Canvas widgets render in element order. So in the hierarchy view,

My Canvas

BackgroundWidget should always appear behind SomeText, without any adjustment to Z-Order. There was a bug previously which allowed elements of the same ZOrder to be rendered in arbitrary order, which may have been doing the ‘correct’ thing for your case, but was a bug.

To be clear - you mean if they have the same z order no adjustments should have to be made?

And thanks for the clarification about painting widgets out of the borders, it sounds like what I was expecting in the first place. I always put my bounds correctly for that reason so doubt that’s the cause of my problems but I’ll need to dig in some more now as it’s gone into pure speculation mode on my part after hearing all problems people are seeing seem to come from things actually working as expected now.


Right, assuming everybody has the same Z-Order, the rendering order flows from Top to Bottom as they’re listed in the Hierarchy view.

Good good, thanks.