(1.2.1) Strange game-ending bug

[SageAcrin]

I'm actually not quite sure what happened here, I went to the Sher'tul Fortress from Dreadfell using the Rod of Recall, uploaded the Bindings of Eternal Night to the vault, and...

Lua Error: [string "d={}..."]:139: attempt to call global 'loadNbject' (a nil value)
At [C]:-1 loadNbject
At [string "d={}..."]:139 deserialize
At /engine/class.lua:348 load
At /engine/Savefile.lua:395 loadObject
At [string "d={}..."]:6796 deserialize
At /engine/class.lua:348 load
At /engine/Savefile.lua:395 loadObject
At [string "d={}..."]:2202 deserialize
At /engine/class.lua:348 load
At /engine/Savefile.lua:395 loadObject
At [string "d={}..."]:118 deserialize
At /engine/class.lua:348 load
At /engine/Savefile.lua:395 loadReal
At /engine/Savefile.lua:529
At /engine/SavefilePipe.lua:294 doLoad
At /engine/Zone.lua:667 load
At /engine/Zone.lua:113 init
At /engine/class.lua:97 new
At /mod/class/Game.lua:840 changeLevelReal
At /mod/class/Game.lua:733 changeLevel
At /mod/class/Game.lua:1742
At /engine/KeyBind.lua:263 triggerVirtual
At /mod/dialogs/MapMenu.lua:75 use
At /mod/dialogs/MapMenu.lua:39 fct
At /engine/ui/List.lua:159 onUse
At /engine/ui/List.lua:82 fct
At /engine/Mouse.lua:56 receiveMouse
At /engine/Mouse.lua:94 delegate
At /engine/ui/Dialog.lua:547 mouseEvent
At /mod/dialogs/MapMenu.lua:53 fct
At /engine/Mouse.lua:56

... got this error in the log. The actual game hung indefinitely on hitting the portal to the world map, endlessly loading. I did upgrade from 1.2 to 1.21 and kept playing, but this was a bit ago and I didn't notice problems until well after, including multiple world map visits...