[MC-304465] Buried Treasure Map generates as an Empty Map in shipwreck/ocean ruin chests when upgrading old worlds

In worlds upgraded to 1.21.11-pre2, in shipwreck and ocean ruin chests a Buried Treasure Map is replaced by an Empty Map that is incorrectly named “Buried Treasure Map”.

To reproduce:

Create a world in an older version of Minecraft (I tried 1.21.10 and 25w45a).
Upgrade the world to 1.21.11-pre2.
Find any shipwreck or ocean ruin chest containing a Buried Treasure Map.
Observe that it contains an Empty Map named “Buried Treasure Map” instead of the correct map.

Linked issues

duplicates 1

MC-218156 Shipwrecks and ocean ruins can generate with empty buried treasure maps Open

Attachments

Comments 3

josh w 2025-11-27T18:16:31Z

for me it was the same but i didn’t upgrade my world

josh w 2025-11-27T18:18:36Z

clamlol 2025-11-27T18:27:42Z

I highly suspect the locations tested by the reported would also have had an empty BTM in the versions in which they were first generated, so I will resolve this as a duplicate of MC-218156.