According to your testing, does the issue occur with ONLY Immersive Portals mod installed?

Yes

Forge Version

neoforge 21.1.208

ImmersivePortals Version

All the versions for neoforge 1.21.1, tried them all

Latest Log

---- Minecraft Crash Report ---- // You should try our sister game, Minceraft! Time: 2025-09-07 22:22:53 Description: Unexpected error java.lang.NoClassDefFoundError: me/shedaniel/cloth/clothconfig/shadowed/org/yaml/snakeyaml/Yaml at TRANSFORMER/[email protected]/qouteall.imm_ptl.core.render.ShaderCodeTransformation.init(ShaderCodeTransformation.java:56) ~[immersive_portals-6.0.3.jar%23191!/:?] {re:mixin,re:classloading} at TRANSFORMER/[email protected]/qouteall.imm_ptl.core.IPModMainClient.lambda$init$4(IPModMainClient.java:79) ~[immersive_portals-6.0.3.jar%23191!/:?] {re:classloading} at TRANSFORMER/[email protected]/net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:148) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B} at TRANSFORMER/[email protected]/net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:23) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,re:computing_frames,re:classloading} at TRANSFORMER/[email protected]/net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:122) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B} at TRANSFORMER/[email protected]/net.minecraft.util.thread.BlockableEventLoop.runAllTasks(BlockableEventLoop.java:111) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B} at TRANSFORMER/[email protected]/net.minecraft.client.Minecraft.runTick(Minecraft.java:1155) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:A,pl:runtimedistcleaner:A} at TRANSFORMER/[email protected]/net.minecraft.client.Minecraft.run(Minecraft.java:807) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:A,pl:runtimedistcleaner:A} at TRANSFORMER/[email protected]/net.minecraft.client.main.Main.main(Main.java:230) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:classloading,pl:runtimedistcleaner:A} at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?] {} at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:136) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.clientService(CommonLaunchHandler.java:124) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonClientLaunchHandler.runService(CommonClientLaunchHandler.java:32) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.lambda$launchService$4(CommonLaunchHandler.java:118) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.run(Launcher.java:103) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.main(Launcher.java:74) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-11.0.5.jar%23112!/:?] {} at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:210) [bootstraplauncher-2.0.2.jar:?] {} at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:69) [bootstraplauncher-2.0.2.jar:?] {} Caused by: java.lang.ClassNotFoundException: me.shedaniel.cloth.clothconfig.shadowed.org.yaml.snakeyaml.Yaml at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at cpw.mods.securejarhandler/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:216) ~[securejarhandler-3.0.8.jar:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at cpw.mods.securejarhandler/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:216) ~[securejarhandler-3.0.8.jar:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} ... 24 more A detailed walkthrough of the error, its code path and all known details is as follows: --------------------------------------------------------------------------------------- -- Head -- Thread: Render thread Stacktrace: at TRANSFORMER/[email protected]/qouteall.imm_ptl.core.render.ShaderCodeTransformation.init(ShaderCodeTransformation.java:56) ~[immersive_portals-6.0.3.jar%23191!/:?] {re:mixin,re:classloading} at TRANSFORMER/[email protected]/qouteall.imm_ptl.core.IPModMainClient.lambda$init$4(IPModMainClient.java:79) ~[immersive_portals-6.0.3.jar%23191!/:?] {re:classloading} at TRANSFORMER/[email protected]/net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:148) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B} at TRANSFORMER/[email protected]/net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:23) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,re:computing_frames,re:classloading} at TRANSFORMER/[email protected]/net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:122) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:accesstransformer:B,re:computing_frames,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B} -- Uptime -- Details: JVM uptime: 21.334s Wall uptime: 3.977s High-res time: 16.793s Client ticks: 0 ticks / 0.000s Stacktrace: at TRANSFORMER/[email protected]/net.minecraft.client.Minecraft.fillReport(Minecraft.java:2394) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:A,pl:runtimedistcleaner:A} at TRANSFORMER/[email protected]/net.minecraft.client.Minecraft.emergencySaveAndCrash(Minecraft.java:868) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:A,pl:runtimedistcleaner:A} at TRANSFORMER/[email protected]/net.minecraft.client.Minecraft.run(Minecraft.java:828) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:A,pl:runtimedistcleaner:A} at TRANSFORMER/[email protected]/net.minecraft.client.main.Main.main(Main.java:230) ~[client-1.21.1-20240808.144430-srg.jar%23189!/:?] {re:classloading,pl:runtimedistcleaner:A} at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?] {} at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:136) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.clientService(CommonLaunchHandler.java:124) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonClientLaunchHandler.runService(CommonClientLaunchHandler.java:32) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.lambda$launchService$4(CommonLaunchHandler.java:118) ~[loader-4.0.41.jar%23107!/:4.0] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.run(Launcher.java:103) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.main(Launcher.java:74) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-11.0.5.jar%23112!/:?] {} at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-11.0.5.jar%23112!/:?] {} at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:210) [bootstraplauncher-2.0.2.jar:?] {} at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:69) [bootstraplauncher-2.0.2.jar:?] {} -- Last reload -- Details: Reload number: 1 Reload reason: initial Finished: No Packs: vanilla -- System Details -- Details: Minecraft Version: 1.21.1 Minecraft Version ID: 1.21.1 Operating System: Windows 10 (amd64) version 10.0 Java Version: 21.0.7, Microsoft Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Microsoft Memory: 151665064 bytes (144 MiB) / 503316480 bytes (480 MiB) up to 4294967296 bytes (4096 MiB) CPUs: 4 Processor Vendor: GenuineIntel Processor Name: Intel(R) Core(TM) i5-6300HQ CPU @ 2.30GHz Identifier: Intel64 Family 6 Model 94 Stepping 3 Microarchitecture: Skylake (Client) Frequency (GHz): 2.30 Number of physical packages: 1 Number of physical CPUs: 4 Number of logical CPUs: 4 Graphics card #0 name: Intel(R) HD Graphics 530 Graphics card #0 vendor: Intel Corporation Graphics card #0 VRAM (MiB): 1024.00 Graphics card #0 deviceId: VideoController1 Graphics card #0 versionInfo: 21.20.16.4550 Graphics card #1 name: NVIDIA GeForce GTX 960M Graphics card #1 vendor: NVIDIA Graphics card #1 VRAM (MiB): 2048.00 Graphics card #1 deviceId: VideoController2 Graphics card #1 versionInfo: 24.21.13.9835 Memory slot #0 capacity (MiB): 4096.00 Memory slot #0 clockSpeed (GHz): 2.13 Memory slot #0 type: DDR4 Memory slot #1 capacity (MiB): 8192.00 Memory slot #1 clockSpeed (GHz): 2.13 Memory slot #1 type: DDR4 Virtual memory max (MiB): 17778.42 Virtual memory used (MiB): 6904.15 Swap memory total (MiB): 5594.56 Swap memory used (MiB): 313.51 Space in storage for jna.tmpdir (MiB): available: 803265.38, total: 952483.00 Space in storage for org.lwjgl.system.SharedLibraryExtractPath (MiB): available: 803265.38, total: 952483.00 Space in storage for io.netty.native.workdir (MiB): available: 803265.38, total: 952483.00 Space in storage for java.io.tmpdir (MiB): available: 803265.38, total: 952483.00 Space in storage for workdir (MiB): available: 803265.38, total: 952483.00 JVM Flags: 8 total; -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M -Xmx4096m -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump Launched Version: neoforge-21.1.206 Launcher name: java-minecraft-launcher Backend library: LWJGL version 3.3.3+5 Backend API: Intel(R) HD Graphics 530 GL version 4.4.0 - Build 21.20.16.4550, Intel Window size: 854x480 GFLW Platform: win32 GL Caps: Using framebuffer using OpenGL 3.2 GL debug messages: Is Modded: Definitely; Client brand changed to 'neoforge' Universe: 400921fb54442d18 Type: Client (map_client.txt) Graphics mode: fancy Render Distance: 12/12 chunks Resource Packs: vanilla Current Language: es_es Locale: es_ES System encoding: Cp1252 File encoding: UTF-8 CPU: 4x Intel(R) Core(TM) i5-6300HQ CPU @ 2.30GHz ModLauncher: 11.0.5+main.901c6ea8 ModLauncher launch target: forgeclient ModLauncher services: sponge-mixin-0.15.2+mixin.0.8.7.jar mixin PLUGINSERVICE loader-4.0.41.jar slf4jfixer PLUGINSERVICE loader-4.0.41.jar runtime_enum_extender PLUGINSERVICE at-modlauncher-10.0.1.jar accesstransformer PLUGINSERVICE loader-4.0.41.jar runtimedistcleaner PLUGINSERVICE modlauncher-11.0.5.jar mixin TRANSFORMATIONSERVICE modlauncher-11.0.5.jar fml TRANSFORMATIONSERVICE FML Language Providers: [email protected] [email protected] [email protected] Mod List: immersive_portals-6.0.3.jar |Immersive Portals |immersive_portals_core |6.0.3 |Manifest: NOSIGNATURE client-1.21.1-20240808.144430-srg.jar |Minecraft |minecraft |1.21.1 |Manifest: a1:d4:5e:04:4f:d3:d6:e0:7b:37:97:cf:77:b0:de:ad:4a:47:ce:8c:96:49:5f:0a:cf:8c:ae:b2:6d:4b:8a:3f neoforge-21.1.206-universal.jar |NeoForge |neoforge |21.1.206 |Manifest: NOSIGNATURE Crash Report UUID: a7725dd2-a1d4-49fa-af47-33e0d5005cf5 FML: 4.0.41 NeoForge: 21.1.206

Crash Report (if applicable)

No response

Steps to Reproduce

1. Have immersive portals in the mods folder
2. Initiate the game
3. Wait to finish loading

What You Expected

bein able to play

What Happened Instead

imediate crash

Additional Details

no aditionals mod loaded, ony immersive portals

Please Read and Confirm The Following

• I have confirmed this bug can be replicated without the use of Optifine.
• I have confirmed the details provided in this report are concise as possible and does not contained vague information (ie. Versions are properly recorded, answers to questions are clear).
• I have confirmed this does not happen on the fabric version (If it does please report to here instead).
• I have confirmed I'm not using a hybrid server (Magma, Cauldron) or a different (non official) Forge Server release.
• I have confirmed this issue is unique and has not been reported already.

You will likely have to roll back your neoforge version to get it to work currently.

Install the required Cloth Config API (Fabric/Forge/NeoForge) mod to solve this issue.