Also, if you want grizzly bears to show up in tropical forests, you need to add [BIOME:ANY_TROPICAL_FOREST] to their entry. Alternatively, if you want them to show up everywhere, you could add [BIOME:ANY_LAND].
Yea that was what I did. Copied the grizzlys from the creature_large_temperate to creature_large_tropical. Im just starting messing with the raws and didnt know it worked the other way. And thanks for showing me how to do it properly.
What you did was something completely other than what he said to do.
Contrary to what you might expect, which raw file a creature is in has nothing whatsoever to do with where the creature appears. The titles of the raw files are purely for the convenience of the modders. The game does not care what the title of the raw file is, it's just taking them all and reading all the data in wherever it comes from. When you took the copy of the grizzly bear data from creature_large_temperate and copied it into creature_large_tropical, you created two identical raws for the same creature in the raw files (the game doesn't care that they're in separate files). Therefore, duplicate raws and a broken world.
What you want to do is restore your raws to the original install state. Then, go to the grizzly bear entry in creature_large_temperate and add the line [BIOME:ANY_TROPICAL_FOREST] to it. Do not make a second grizzly bear entry anywhere in the raws, do not touch creature_large_tropical or any other raw file.