1.18.2 Errors in currently selected datapacks prevented world from loading

[kalakunlun]

I have a world created with a custom 1.18.1 Modpack, and now I am trying to upgrade it into 1.18.2.

I replaced all mods from the original pack into their 1.18.2 versions. The new pack is launched successfully, but when I try to load the old world, it says "Errors in currently selected datapacks prevented world from loading".

 

Based on my own experiences, upgrading the mods and load an old world may have problems if it contains some blocks/items/entities which is already removed in the newer versions.

However, I am sure that the world does not contain any of removed blocks/items/entities. Also,

 When I tried to load a world created with the old 1.18.1 pack containing only vanilla elements, it shows the exactly same error message.

 When I tried to load a world created with vanilla minecraft, but have been loaded, modified and saved with the old 1.18.1 pack, it opens successfully.

It makes me even more confused what the problem is.

 

Both the old 1.18.1 pack and the 1.18.2 pack only have built-in resources packs loaded. (Default Minecraft, mod resources and a built-in resource pack for the mod supplementaries)

 

The debug log file is pasted here:

https://pastebin.com/LB9niyib

I have also checked the log myself before, but have got not idea what happened. The errors don't seem to point to a specific mod or a data pack.

[warjort]

Your actual error is

Quote

[097月2022 23:50:18.302] [Render thread/ERROR] [net.minecraft.world.level.storage.LevelStorageSource/]: Exception reading D:\Qu'y_a-t-il_dedans\Jeux\mcmc\saves\New World (1)\level.dat_old

java.util.NoSuchElementException: No value present

at java.util.Optional.orElseThrow(Optional.java:377) ~[?:?]

at net.minecraft.util.datafix.fixes.StructureSettingsFlattenFix.m_204014_(StructureSettingsFlattenFix.java:27) ~[client-1.18.2-20220404.173914-srg.jar%23109!/:?]

This is a Mojang DataFix that looks to be related to changes made in 1.18.2 to support the new feature:

https://www.minecraft.net/en-us/article/minecraft-java-edition-1-18-2

Quote

It is now possible to add custom structures in experimental datapacks

So there is probably something about the modded structures in your world save from 1.18.1 that does not follow the vanilla format and so can't be fixed.

There would have been no standard format for this before the feature was added in 1.18.2

There is also these warnings:

Quote

[097月2022 23:50:08.674] [Render thread/WARN] [net.minecraftforge.registries.GameData/REGISTRIES]: Missing Registries:

tconstruct:modifiers

 

[097月2022 23:50:08.748] [Render thread/ERROR] [net.minecraftforge.registries.GameData/REGISTRIES]: Unidentified mapping from registry minecraft:block

create:furnace_engine: 2175

 

[097月2022 23:50:08.749] [Render thread/ERROR] [net.minecraftforge.registries.GameData/REGISTRIES]: Unidentified mapping from registry minecraft:item

create:furnace_engine: 2956

create:incomplete_cogwheel: 3059

create:incomplete_large_cogwheel: 3060

 

[097月2022 23:50:08.750] [Render thread/ERROR] [net.minecraftforge.registries.GameData/REGISTRIES]: Unidentified mapping from registry minecraft:sound_event

minecolonies:tile.sawmill.saw: 3058

supplementaries:block.tick_1: 1376

supplementaries:block.tick_2: 1377

supplementaries:block.tom: 1375

 

[097月2022 23:50:08.750] [Render thread/ERROR] [net.minecraftforge.registries.GameData/REGISTRIES]: Unidentified mapping from registry simpleplanes:upgrade_types

simpleplanes:tnt: 10

 

[097月2022 23:50:08.751] [Render thread/WARN] [net.minecraftforge.registries.GameData/REGISTRIES]: Forge Mod Loader detected missing registry entries.

 

There are 9 missing entries in this save.

If you continue the missing entries will get removed.

A world backup will be automatically created in your saves directory.

 

The only thing I can suggest is to identify your worldgen mods that add structures and talk to the mod authors.

They may have a solution to this problem?