A mod crashed on startup!
net.fabricmc.loader.impl.FormattedException: java.lang.RuntimeException: Could not execute entrypoint stage 'preLaunch' due to errors, provided by 'libjf-base' at 'io.gitlab.jfronny.libjf.LibJf'!
at net.fabricmc.loader.impl.FormattedException.ofLocalized(FormattedException.java:63)
at net.fabricmc.loader.impl.launch.knot.Knot.init(Knot.java:162)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:68)
at net.fabricmc.loader.impl.launch.knot.KnotServer.main(KnotServer.java:23)
at net.fabricmc.loader.impl.launch.server.FabricServerLauncher.main(FabricServerLauncher.java:69)
at net.fabricmc.installer.ServerLauncher.main(ServerLauncher.java:69)
Caused by: java.lang.RuntimeException: Could not execute entrypoint stage 'preLaunch' due to errors, provided by 'libjf-base' at 'io.gitlab.jfronny.libjf.LibJf'!
at net.fabricmc.loader.impl.FabricLoaderImpl.lambda$invokeEntrypoints$2(FabricLoaderImpl.java:403)
at net.fabricmc.loader.impl.util.ExceptionUtil.gatherExceptions(ExceptionUtil.java:33)
at net.fabricmc.loader.impl.FabricLoaderImpl.invokeEntrypoints(FabricLoaderImpl.java:401)
at net.fabricmc.loader.impl.launch.knot.Knot.init(Knot.java:160)
... 4 more
Caused by: java.lang.RuntimeException: Mixin transformation of io.gitlab.jfronny.commons.logger.DelegateLogger failed
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:427)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:323)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:218)
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:119)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
at knot//io.gitlab.jfronny.libjf.LibJf.bootstrap(LibJf.java:51)
at knot//io.gitlab.jfronny.libjf.LibJf.setup(LibJf.java:35)
at knot//io.gitlab.jfronny.libjf.LibJf.onPreLaunch(LibJf.java:29)
at net.fabricmc.loader.impl.FabricLoaderImpl.invokeEntrypoints(FabricLoaderImpl.java:399)
... 5 more
Caused by: org.spongepowered.asm.mixin.throwables.MixinApplyError: Mixin [owo.mixins.json:DataResultMixin from mod owo] from phase [DEFAULT] in config [owo.mixins.json] FAILED during PREPARE
at org.spongepowered.asm.mixin.transformer.MixinProcessor.handleMixinError(MixinProcessor.java:638)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.handleMixinPrepareError(MixinProcessor.java:585)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.prepareConfigs(MixinProcessor.java:543)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.select(MixinProcessor.java:462)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.checkSelect(MixinProcessor.java:438)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:290)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:234)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:202)
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:422)
... 13 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTargetAlreadyLoadedException: Critical problem: owo.mixins.json:DataResultMixin from mod owo target com.mojang.serialization.DataResult was loaded too early.
at org.spongepowered.asm.mixin.transformer.MixinInfo.readDeclaredTargets(MixinInfo.java:947)
at org.spongepowered.asm.mixin.transformer.MixinInfo.(MixinInfo.java:881)
at org.spongepowered.asm.mixin.transformer.MixinConfig.prepareMixins(MixinConfig.java:933)
at org.spongepowered.asm.mixin.transformer.MixinConfig.prepare(MixinConfig.java:858)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.prepareConfigs(MixinProcessor.java:540)
... 19 more

latest.log

A full crash report and log would assist to further find what may be the cause but such may require you search your pack to find the exact mod doing this.

Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTargetAlreadyLoadedException: Critical problem: owo.mixins.json:DataResultMixin from mod owo target com.mojang.serialization.DataResult was loaded too early.

Seems like someone is attempting to load the DataResult class from DFU within some prelaunch before mixins are applied which is leading to crashing