In side collisium there is a pool with a small door above it. (where the last tablet lies) On either side is a hallway leading to a door. Both doors need a glowstone and behind each door is a switch. No matter what I do the door above the pool does not open. I have done this before but it don't seem to work now. Ideas?

I figured it out you need both glowstones in place.

Glad you figured it out!

Have heard that someone manage to do this puzzle by blocking one door to be able to use the glowstone on the other but it was extremely difficult to accomplish.

Wyv