Hardcore world incorrectly detected as Flat World and other settings in 26.50

After updating Minecraft Bedrock Edition from version 26.45 to 26.50, an existing Hardcore world started incorrectly reporting multiple reasons for why achievements cannot be earned. The world was never created as a Flat World, was never created in Creative mode, and was not created from a template. The world still has normal terrain.

Steps to reproduce the problem

1. Have an existing Hardcore world with normal terrain generation.

2. Use an add-on in the world for a short period of time.

3. Update Minecraft Bedrock Edition from version 26.45 to version 26.50.

4. Open the same world after updating.

5. Open the world settings.

6. Open the “You can't earn achievements” message.

7. Check the reasons listed as disabling achievements.

Expected result

The game should correctly detect the settings of the existing world. Since the world was created as a normal Hardcore world and was never created as a Flat World, Creative world, or template world, those options should not be listed as reasons for disabling achievements.

Actual result

After updating to version 26.50, the game incorrectly reports that the world was created as a Flat World and also lists other conditions that were never used for this world, such as Creative mode and a template.

The world itself still has normal terrain and was not converted into a Flat World.

The issue was first noticed immediately after updating to version 26.50. Other worlds do not have this problem. Copies of this specific world, including copies made before and after the issue appeared, also show the same incorrect achievement warning.

Additional information

• Version before the issue: 26.45

• Version where the issue appeared: 26.50

• The world is Hardcore.

• The world has normal terrain generation.

• The world was never created as a Flat World.

• The world was never created in Creative mode.

• The world was never created from a template.

• The issue appeared immediately after the 26.50 update.

• Only this world and its copies are affected.