Problem with Biomes #575

Greetings, I'm a first time user of the mod, and I"m trying attempting to use the custom biome bundle. My goal is to generate the terrain for use in a server, and then remove the mod as to leave the terrain but not require joining members to have the mod installed. I want to designate the biomes that the custom ones revert to, so for example Savanna Edge would become just Savanna. However, when I try to change ReplaceToBiomeName to taiga for Savanna Edge as a test, it freezes up when trying to reload the world. Am I doing this incorrectly, or is it just not possible?