I was in creative mode testing out some things with a variety of mods I was using, and when I tried to use a Redstone Furnace to test the efficiency of a specific modded dynamo I was using, it crashed. I went back in tried to use the furnace while it wasn't connected to any dynamo whatsoever, and it still crashed. Then, I looked in the crash report and saw that a GUI error relating to the LOTR mod seemed to be at fault. I uninstalled the LOTR mod and tried again, and it worked perfectly. After reinstalling the LOTR mod, it would crash again.
Any ideas on how to fix this bug, and what exactly the bug is?