As you have played already a long time I assume the game was working correctly before.
Anything you did in inbetween, like command line edits or installing Mods or URM? If that is the case your game state may have become corrupted. That cannot be healed.
Just for trial:
You can give yourself the Crystal Plug by
GAME.mc.addItem("ITMPlugCrystal")
by command line though it might not bring things back on track. Maybe that helps.
The game has been downloaded by 100k Users so far and this major error has not been reported once, so I really don't know whats going on.
EDIT: Researching the 'unicode is not callable' error I would assume what happened is you used GAME.mc.addItem in the command line in a wrong way, thus destroying the function addItem() permanently. Only way to recover is to go back to a save before you did that (if that is what happened).