GUI issues for 4.0

Bugs
1

My UI I made to do WebM video recording with integrated audio is no-longer running as before. It runs using the current cdn media, but not preview. Here is the before /after:

UI%20combined
UI combined.png750×1002 317 KB

It looks like it does not like radio buttons stacked vertically. I get like 100 warnings. Here are the examples of each message type:

babylon.js:16 BJS - [11:06:19]: Control (Name:header, UniqueId:27) is using width in percentage mode inside a horizontal StackPanel

and
babylon.js:16 BJS - [11:06:19]: Control (Name:undefined, UniqueId:23) is using height in percentage mode inside a vertical StackPanel

For this particular video, which is ironically a demo of my new XR-UIPortal, I can easily just use production, but thought now is the time to speak up.

2

This is because you have horizontal stack panel and instead of using pixels you have percentage. V3. 3 dealt weirdly with that causing several issues (you were lucky but 100% sure that values are incorrect even though is looks OK)
For 4.0 I fixed it and to be sure I emit this warning.

Overall the idea is that stack panel will compute its size based on its content so the content cannot have a percentage of its parent or else its gonna be an infinite loop