In my project I have several places where I have a grid that is initially invisible, but then becomes visible after some actions are taken. Used to work fine till the weekend's update.
Now, if the grid starts out hidden, it can never be shown. However if it starts out visible, it can be hidden then shown.
I have shared a project called Problems10-20-14 with Support, which illustrates the problem. Ignore the bottom part of the screen, this is a different problem, for which I will open another bug report.