. . Ok, just found the reason.
. . Debugging a little more into the code, it seems that the root of the problem is the tweens linked list. It seems that at some point, when removing a tween, it points the "next" of a tween to another instance that is "before" the "current", so it will loop through that range indefinitely (like, the "next" on the _6_ is pointing to the _2_, so it will go: "2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6" over and over again).
. . The biggest of the problems: I have no clue whatsoever of what may be causing it, and it happens very randomly during the gameplay. Sometimes I'm just walking, sometimes I'm chatting, sometimes I'm in the middle of a multiplayer game... For now I'm probably switching to another tween library until I find a way to efficiently debug the code.
. . Any tips? Keep in mind that it happens very randomly and right now the only debugging technique I can use is to write a *HUGE* log and then analyze the contents after the crash. I tried breakpoints, but since it happens with no pattern, I can only detect the moment after it happened and I'm not able to go back on time and check the values and what happened before.