Sorry for the late reply. Converting something from post 1.13 into 1.12 is a bit tricky because of The Flattening. A method I know works is pasting the build into a world, then converting the world to 1.12 using Jupisoft's Minecraft Tools (https://www.minecraftforum.net/forums/mapping-and-modding-java-edition/minecraft-tools/2947154-minecraft-tools-in-c-for-1-14-with-full-source). Remember to specify what you want newer blocks converted to (like honey blocks to yellow terracotta) - otherwise it might end up rather strange looking.
Amphitheatre Arena [1.15] on July 13th, 2020 03:46 PM EST