I rechecked everything and it all seemed fine. I also ran the scenario and produced the fire catapult whose unit folder is next to the Woad warrior folder. No problem there. I also tried producing the Woad Warrior differently in the queue. The crashes came but at different times: when auto changing to WW from a just produced spearman and when finished producing Woad warrior and had to show it in game. Same message. So I played it with England (only civ with this unit) as an AI; game crashed first turn. Same error. Not looking good. I opened each flc file in quicktime and all worked.
Then I added another unit: Spartan Hoplite. Followed tha same procedure, but gave it to Greece. All files in the same places as Woad Warrior. I played the game without England. Spartan Hoplite was built without a problem!!
It appears that the problem is with Woad Warrior and not more general, I can add units, good! Does this help you see what the problem with Woad Warrior might be?