I want to highlight a very concerning change to the uGUI layout system in the 5.5 update. There has been an introduction of new layout ground properties example: “Control Child Size”.
As far as I can see there has been no mention of these changes in any of the release notes for 5.5 RC’s or patches / betas onward. There is no documentation available for these new controls in any manual or scripting reference.
It is as if someone at Unity mistakenly committed development code and QA didn’t catch it because these changes appear to be MAJORLY broken!!! After their introduction layout group controlled UI elements no longer behave by predictable rules, even when constrained by parent properties some children are often still able to be manually manipulated in the editor ( Didn’t happen in 5.4 ) and other times layout groups cause destructive changes to child element properties ( mostly collapsing children sizes ). These destructive changes cannot be undone, and if you happen to use layout groups in any nested context you will discover how damaging these “Hidden features” are.
You really should give some more info on what you mean by broken so that others can see if they are having similar issues. I upgraded to 5.5 and have personally not had any issues with any of my layout groups.
I do agree that the feature is undocumented, so it’s true purpose is confusing. I may just be lucky or haven’t hit the exact setup that will produce the issue. Hopefully they will be able to look into it.