What mods are side-loaded does not affect unearthed's result.

Exception in thread "main" [13:11:52] [main/INFO]: [STDERR]: java.lang.RuntimeException: Failed to setup Fabric server environment! [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.server.FabricServerLauncher.main(FabricServerLauncher.java:51) [13:11:52] [main/INFO]: [STDERR]: Caused by: java.lang.RuntimeException: java.lang.RuntimeException: An exception occurred when launching the server! [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.server.FabricServerLauncher.setup(FabricServerLauncher.java:107) [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.server.FabricServerLauncher.main(FabricServerLauncher.java:49) [13:11:52] [main/INFO]: [STDERR]: Caused by: java.lang.RuntimeException: An exception occurred when launching the server! [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.server.FabricServerLauncher.launch(FabricServerLauncher.java:63) [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.server.FabricServerLauncher.setup(FabricServerLauncher.java:105) [13:11:52] [main/INFO]: [STDERR]: ... 1 more [13:11:52] [main/INFO]: [STDERR]: Caused by: java.lang.reflect.InvocationTargetException [13:11:52] [main/INFO]: [STDERR]: at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [13:11:52] [main/INFO]: [STDERR]: at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) [13:11:52] [main/INFO]: [STDERR]: at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [13:11:52] [main/INFO]: [STDERR]: at java.base/java.lang.reflect.Method.invoke(Unknown Source) [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.server.FabricServerLauncher.launch(FabricServerLauncher.java:61) [13:11:52] [main/INFO]: [STDERR]: ... 2 more [13:11:52] [main/INFO]: [STDERR]: Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:229) [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.knot.Knot.init(Knot.java:140) [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.launch.knot.KnotServer.main(KnotServer.java:26) [13:11:52] [main/INFO]: [STDERR]: ... 7 more [13:11:52] [main/INFO]: [STDERR]: Caused by: java.lang.reflect.InvocationTargetException [13:11:52] [main/INFO]: [STDERR]: at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [13:11:52] [main/INFO]: [STDERR]: at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) [13:11:52] [main/INFO]: [STDERR]: at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [13:11:52] [main/INFO]: [STDERR]: at java.base/java.lang.reflect.Method.invoke(Unknown Source) [13:11:52] [main/INFO]: [STDERR]: at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:227) [13:11:52] [main/INFO]: [STDERR]: ... 9 more [13:11:52] [main/INFO]: [STDERR]: Caused by: java.lang.NoSuchMethodError: 'boolean net.minecraft.class_2378.method_10250(net.minecraft.class_2960)' [13:11:52] [main/INFO]: [STDERR]: at net.oriondevcorgitaco.unearthed.util.RegistrationHelper.registerFeature(RegistrationHelper.java:20) [13:11:52] [main/INFO]: [STDERR]: at net.oriondevcorgitaco.unearthed.world.feature.naturalgenerators.NaturalGenerator.<clinit>(NaturalGenerator.java:25) [13:11:52] [main/INFO]: [STDERR]: at net.minecraft.server.MinecraftServer.<clinit>(MinecraftServer.java:175) [13:11:52] [main/INFO]: [STDERR]: at net.minecraft.server.Main.main(Main.java:116) [13:11:52] [main/INFO]: [STDERR]: ... 14 more

Could you send your modlist and a copy paste of your crash with https://hatebin.com/

The mods are Fabric API, Lithium, and Phosphor, even with only fabric API the crash happens.
Edit: Forgot to mention I also run Java11+
https://hatebin.com/asbagnvhsy Full log.

Crashing still persists on v1.0.3 on stock Fabric Server with Fabric API.

This happens on the forge version aswell (using only unearthed)

@rafaelkai send your crashlog and latest.log

latest.log: https://hatebin.com/mohvlrftwm

The issue doesn't seem to generate a crashlog

Same for me - only unearthed and fabric api

https://hatebin.com/mzrjqmulmt

Patched: [Forge 1.16.2/3] https://www.curseforge.com/minecraft/mc-mods/unearthed-forge/files/3089010
[Fabric 1.16.2/3] https://www.curseforge.com/minecraft/mc-mods/unearthed-fabric/files/3089015