Have you changed the default controls? I changed the mapping of WASD to other buttons I found more comfortable, and had the same issue of the game hanging when collecting the instrument. Exiting to main menu and going back in did nothing, closing the program and reopening it worked, so I assumed that was the trick. However, I had the same issue on the second instrument. I closed and reopened, remapped my controls again since the walk through the second dungeon is slightly longer than the first, and had it hang again despite the restart. I restarted again, walked there with default controls, and it didn't hang.