Minecraft 1.8.8, Minecraft 15w49b, Minecraft 16w42a, Minecraft 1.11.2, Minecraft 1.12.1, Minecraft 1.12.2, Minecraft 18w01a, Minecraft 18w07c, Minecraft 1.13, Minecraft 18w30b, Minecraft 18w31a, Minecraft 18w32a, Minecraft 18w33a, Minecraft 1.13.1-pre1, Minecraft 1.13.1, Minecraft 1.13.2, Minecraft 19w03b, Minecraft 19w03c, 20w21a, 20w51a, 1.16.5, 1.17.1
When you have a world with seed zero, i.e. when
outputs 0, then it cannot be recreated using the "Re-Create" option, because it will be interpreted as a random seed. To be clear, I know that putting "0" in the seed option is supposed to create a random world. However, I would expect that copying an existing world with seed 0 would also generate a world with seed 0.
How to reproduce
As mentioned, putting '0' in the seed option on the "Create New World" screen will be interpreted as a random seed (Personally I find this unintuitive behavior, but this has been resolved as intended:
MC-1820). However, a world with the seed 0 can be generated either through external tools, or by choosing the seed text very carefully. Here are some options for the text, that will generate a world with seed 0:
tainsntoh f5a5a608 af4e962cd