menu editor becomes unresponsive in IE11

In IE11 on Windows 7, the menu editor becomes unresponsive after several clicks in the tree. I don't have a precise reproduction path, but if you open/close/click (no drags) menu items, it freezes here after a 10-30 of clicks. Attached also an image of the structure of the tree. When you watched me clicking about you had the suspicion it was on collapsing an item.