Minecraft Server - Does the map stay downgrade?

Wanted to ask what happens: If I changed my Minecraft server from 1.13.2 to 1.12, would not the world work? Or you can continue to play just normal without the features of 1.13.2?

I'm just at Vanilla snapshot-18w43c, and since this snapshot pisses me off on the ghost and we've already built a cool map, I do not want the map to go wrong with another version…

Does anyone have an answer?

A world downgrade from versions 1.13 or higher to versions 1.12.2 or lower is not possible.

The storage format has been changed.

Ouch, that hurts. Okay, then I have to watch how I do that, haha. Just go the map on it.

Save the world and try out.

You could try to create a "schematic" using World Edit

You just have to save the "world" folder

1.13 has changed a lot. That does not work.

But that would not work because of new blocks alone.