Board Thread:Bug Reports/@comment-27516710-20160807002356

How to duplicate: create a spawner in a clean world with beta 27 (or visit a Near Harad pyramid), reload world in beta 28.x, spawners are cleared and any attempt to right-click on them in creative to adjust them causes the game to crash. This bug affects all Near Harad pyramids generated prior to beta 28 which can possibly lead to client crashes.

 