I tried copying animals.ztd and animals2.ztd from the original ZT disc and replacing the installed files. The blank tile is still there, but I can select it. If I click the "info" button, the game crashes again. It looks like it is the same as the user-created invisibility problem. I can actually select the empty tile from the animal adoption screen and place an invisible animal into an exhibit. The game shows some squares for the animals name, but the Ibex is the only thing missing from the adoption menu.
No, I have no user created things installed. I don't even have any official updates installed. Currently, I don't even have the expansions installed, just the US version of ZT1.
Is this weird or what? Any other ideas?