Beta UI 4.6 - Red Cross on runtime objects

As you can see on the picture below, there is a huge red cross on top of my yellow button. This is only showing in the Scene view and not on the Game view.

The button is instantiated at runtime (while pressing the more button above) and all following creations also contain the red cross.
Console does not say anything.

Any idea?

[31991-new+bitmap+image.png|31991]

It looks like there’s an image that is backwards on top of your button, check that it doesn’t have a negative width or height.