I don't know why I get that error:
Unable to activate constraint with anchors <NSLayoutDimension:0x3010bff80 "AIComponentKit.MAIButton:0x1253951f0.width"> and <NSLayoutDimension:0x30117a6c0 "Root View.width" (names: Root View:0x1038b8a40)> because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal.. Irritants: ()
There is a bug in our layout engine that causes this. This happens when you have a component that uses a percentage sizing within another arrangement that is set to be invisible at the start. App Inventor ends up adding the percentage sizing constraint to the screen but the view itself isn't attached (because its parent is invisible), which generates this error. I believe there is a temporary workaround where you make the arrangement visible by default but then set it to be invisible in the Initialize block.
Köszönöm a választ