Lego Harry Potter years 1-4 Library glitch

I've seen a lot of comments in my video about the Last Gold Brick that I made that people are playing the game and there's a gold brick indicator in the Library and the can't figure out what to do, Based on the comments I thought it had to do with the brown hats but I was wrong. I've done some research and I've found the answer. Watch the video and you'll see how your game might be glitched. Enjoy!
my blog: www.lifeofagamergirl.blogspot.com
my twitter: @PengwennGamer
#legoharrypotter #library #glitch