Repeating Error (freezes game) "doTeluvortaSwap"

[omni]

I had just entered into the rift with a host of shadows to see a teluvorta and a greater whatsisname.

They swapped places whilst coming towards me a few times as I moved out into more open ground, and then one of my shadows phased and engaged the teluvorta whilst me and the others began fighting the greater whatsisname with debree seperating the two groups.

Suddenly I get an error that keeps calling repeatedly, preventing me from typing in the bug box or doing anything besides ctrl-alt-delete to kill the game.

Here's my error log:

...
[LOG] Today is the 80th Haze of the 122nd year of the Age of Ascendancy of Maj'Eyal.
The time is 05:41.
Lua Error: /data/general/npcs/telugoroth.lua:164: attempt to call upvalue 'doTeluvortaSwap' (a nil value)
At [C]:-1 doTeluvortaSwap
At /data/general/npcs/telugoroth.lua:164 on_act
At /mod/class/Actor.lua:533 act
At /mod/class/NPC.lua:39 act
At /engine/GameEnergyBased.lua:131 tickLevel
At /engine/GameEnergyBased.lua:62 tick
At /engine/GameTurnBased.lua:44 tick
At /mod/class/Game.lua:904
---------------- Stack Dump ----------------
2: table // 2c25ee8
1: table // 2c25ee8
...

repeats ad infinitum.