Underwater ruin structure files cannot be found

Screenshots portray issue from MC-129625. May be duplicate, but need to see the server logs from the other ticket's console.

Mod FVbico, in editing the description, I fear that you may have removed some failed structure loads related to kelp and sea grass (which the screenshots portray). Your tickets, so you make the rules, just wanna make sure it's tracked somewhere 😉

Edit: I see that they were server WARNs and not ERRORs like the failed structure loading.

Edit 2: Attached WARNs to ticket referenced above.

Luke, not the same issue.

Obviously, the issue will need to be corrected, but a temporary workaround can be achieved by creating a datapack containing the contents of the "underwater_ruin" directory from the JAR under a directory just called "ruin".  This will allow the world to load and generate chunks correctly.

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

Please check if that's still an issue for you in 1.13.1.