The locatebiome command can try to locate biomes that do not exist. This can be because the player is in the wrong dimension for the biome or the biome will never generate. The game takes several seconds to look for the biomes.

Examples:

• /locatebiome minecraft:deep_warm_ocean (never generates with Default worlds)
• /locatebiome minecraft:mountain_edge (never generates with Default worlds)
• /locatebiome minecraft:nether_wastes (when in Overworld of a Default world)

What should happen: There should be a check on whether biome generation is possible. If it is not possible, the message should say "Biome does not exist" (for biomes that never generate) or "Biome does not exist in this dimension".