Crash minecraft forge 1.8.9

[Aegon]

Bonjour,
Je joue depuis quelques jours en 1.8.9 avec quelques mods. Je n'avais aucun soucis pour jouer mais ce soir, j'ai lancé mon jeu avec forge comme d'habitude et lorsque je clique sur "singleplayer" mon jeu crash.

Le message suivant apparaît: "Plantage du jeu: Il semblerait que vous utilisez une version modifiée du jeu non prise en charge".

Voici le latest.log:

[20:36:16] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[20:36:16] [main/INFO]: Using primary tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[20:36:16] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLTweaker
[20:36:16] [main/INFO]: Forge Mod Loader version 11.15.1.1722 for Minecraft 1.8.9 loading
[20:36:16] [main/INFO]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_51, running on Windows 10:amd64:10.0, installed at C:\Program Files (x86)\Minecraft\runtime\jre-x64\1.8.0_51
[20:36:16] [main/WARN]: The coremod ivorius.ivtoolkit.IvToolkitLoadingPlugin does not have a MCVersion annotation, it may cause issues with this version of Minecraft
[20:36:16] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[20:36:16] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[20:36:16] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[20:36:16] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[20:36:16] [main/INFO]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[20:36:20] [main/INFO]: Found valid fingerprint for Minecraft. Certificate fingerprint cd99959656f753dc28d863b46769f7f8fbaefcfc
[20:36:20] [main/ERROR]: FML appears to be missing any signature data. This is not a good thing
[20:36:20] [main/INFO]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[20:36:20] [main/INFO]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[20:36:20] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[20:36:21] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.TerminalTweaker
[20:36:21] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.TerminalTweaker
[20:36:21] [main/INFO]: Launching wrapped minecraft {net.minecraft.client.main.Main}
[20:36:23] [Client thread/INFO]: Setting user: AegonIII
[20:36:31] [Client thread/INFO]: LWJGL Version: 2.9.4
[20:36:32] [Client thread/WARN]: =============================================================
[20:36:32] [Client thread/WARN]: MOD HAS DIRECT REFERENCE System.exit() THIS IS NOT ALLOWED REROUTING TO FML!
[20:36:32] [Client thread/WARN]: Offendor: com/sun/jna/Native.main([Ljava/lang/String;)V
[20:36:32] [Client thread/WARN]: Use FMLCommonHandler.exitJava instead
[20:36:32] [Client thread/WARN]: =============================================================
[20:36:33] [Client thread/INFO]: [net.minecraftforge.fml.client.SplashProgress:start:246]: ---- Minecraft Crash Report ----

WARNING: coremods are present:
  IvToolkit (IvToolkit-1.2.6.jar)
Contact their authors BEFORE contacting forge

// I feel sad now :(

Time: 11/02/19 20:36
Description: Loading screen debug info

This is just a prompt for computer specs to be printed. THIS IS NOT A ERROR


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
    Minecraft Version: 1.8.9
    Operating System: Windows 10 (amd64) version 10.0
    Java Version: 1.8.0_51, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 845670768 bytes (806 MB) / 1073741824 bytes (1024 MB) up to 2147483648 bytes (2048 MB)
    JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML:
    Loaded coremods (and transformers):
IvToolkit (IvToolkit-1.2.6.jar)
 
    GL info: ' Vendor: 'Intel' Version: '4.4.0 - Build 20.19.15.4963' Renderer: 'Intel(R) HD Graphics 5500'
[20:36:34] [Client thread/INFO]: MinecraftForge v11.15.1.1722 Initialized
[20:36:34] [Client thread/INFO]: Replaced 204 ore recipies

EDIT: Je souligne que même en lançant la 1.8.9 sans forge, le jeu plante dès que j'appuis sur singleplayer. Aucun soucis dans multiplayer.
Merci d'avance !