walldi1
Comments
I found the fix for the problem.
You have to copy the "ruin" folder from 18w19b into 18w20b "structure" folder.
Then copy .nbt data from both folder ( "underwater_ruin" from 18w20b + "ruin" from 18w19b ) into the other.
In the end you must have folder "underwater_ruin" and "ruin" in folder "structures" with .nbt data from both versions in both folders.
Hope you understand
I test the idear from @unknown but didn't change anything
18w20b the same. This time with
structure minecraft:ruin/ruin_warm6
structure minecraft:ruin/ruin_warm7
structure minecraft:ruin/big_ruin_warm5
Sorry. I don't upgrade an old World. I create a complete new world with complete new data.
In the other case you can see that anything is missing.
In my case if Server want load it instand crash
i think i found a way to fix this for server.jar .
You have to copy the "ruin" folder from 18w19b into 18w20b "structure" folder.
Then copy .nbt data from both folder ( "underwater_ruin" from 18w20b + "ruin" from 18w19b ) into the other.
In the end you must have folder "underwater_ruin" and "ruin" in folder "structures" with .nbt data from both versions in both folders.
Hope you understand