A while ago I had a problem with the container subclass BetterContainerControl. See https://forum.xojo.com/20998-event-for-container-coming-to-front . Eli Ott made a version that didn’t have the crash that I originally had. Unfortunately, I didn’t test fully 2 months ago. The crash didn’t occur again, but the new code doesn’t do anything. The VisibilityChanged even doesn’t fire when it should. For an example see https://conbr.io/d/x2MFTamm
Mac OS 10.10.2, Xojo 2015r2.