World Preview (Unofficial Port)

Evidence

Ran on Kiln's test stand (2026-11-04): WorldPreview did not start: java.lang.NoClassDefFoundError: net/minecraft/server/MinecraftServer; WorldPreviewClient did not start: java.lang.NoClassDefFoundError: net/minecraft/client/renderer/texture/AbstractTexture.

What it needs from Kiln

• an access widener
• Mixin
• com.mojang.authlib.GameProfile
• com.mojang.blaze3d.platform.NativeImage
• net.fabricmc.loader.api.ModContainer
• net.fabricmc.loader.api.metadata.ModMetadata
• net.minecraft.client.renderer.RenderPipelines
• net.minecraft.client.renderer.texture.AbstractTexture
• net.minecraft.client.renderer.texture.TextureManager
• net.minecraft.commands.Commands
• net.minecraft.commands.Commands.CommandSelection
• net.minecraft.core.BlockPos.MutableBlockPos
• net.minecraft.core.HolderGetter
• net.minecraft.core.LayeredRegistryAccess
• net.minecraft.core.QuartPos
• net.minecraft.core.RegistryAccess
• net.minecraft.core.RegistryAccess.Frozen
• net.minecraft.core.SectionPos
• net.minecraft.server.MinecraftServer
• net.minecraft.server.ReloadableServerResources
• net.minecraft.server.Services
• net.minecraft.server.WorldLoader
• net.minecraft.server.WorldLoader.PackConfig
• net.minecraft.server.WorldStem
• net.minecraft.server.level.progress.LevelLoadListener
• net.minecraft.server.level.progress.LevelLoadListener.Stage
• net.minecraft.server.notifications.NotificationManager
• net.minecraft.server.notifications.NotificationService
• net.minecraft.server.packs.repository.PackRepository
• net.minecraft.server.packs.repository.ServerPacksSource
• net.minecraft.server.packs.resources.CloseableResourceManager
• net.minecraft.server.permissions.LevelBasedPermissionSet
• net.minecraft.server.permissions.PermissionSet
• net.minecraft.server.players.PlayerList
• net.minecraft.util.FileUtil
• net.minecraft.util.Util
• net.minecraft.util.datafix.DataFixers
• net.minecraft.util.debugchart.SampleLogger
• net.minecraft.world.Difficulty
• net.minecraft.world.level.ChunkPos
• net.minecraft.world.level.GameType
• net.minecraft.world.level.LevelHeightAccessor
• and 38 more

On the roadmap: Minecraft's libraries and client API (0.2), Code next to data (0.3), Mixin (0.5)

In the author's words

Allows you to preview a map / seed in the new world screen. Community fork ported to Minecraft 1.20.1, 1.21.1, 1.21.11, 26.1.2, 26.2 and 26.3 with new features and a redesigned UI.

Scan

Scanned on 4 November 2026 against Kiln 0.2.0, file world_preview-1.5.5.jar. The scan reads the mod's classes; it does not run them.