Hi People. So I recently installed the second latest Forge for 1.15.2 (34.1.45)

Here is the Error log:

---- Minecraft Crash Report ----
// I feel sad now

Time: 17/04/20 7:22 PM
Description: Initializing game

java.lang.NoClassDefFoundError: Could not initialize class net.minecraft.util.registry.Registry
    at net.minecraft.util.registry.Bootstrap.func_151354_b(Bootstrap.java:34) ~[?:?] {re:classloading}
    at net.minecraft.client.Minecraft.<init>(Minecraft.java:353) [?:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.main.Main.main(SourceFile:166) [?:?] {re:classloading}
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51] {}
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_51] {}
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51] {}
    at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51] {}
    at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:56) [forge-1.15.2-31.1.45.jar:31.1] {}
    at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$399/322830747.call(Unknown Source) [forge-1.15.2-31.1.45.jar:31.1] {}
    at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-5.0.0-milestone.4.jar:?] {}
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-5.0.0-milestone.4.jar:?] {}
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-5.0.0-milestone.4.jar:?] {}
    at cpw.mods.modlauncher.Launcher.run(Launcher.java:81) [modlauncher-5.0.0-milestone.4.jar:?] {}
    at cpw.mods.modlauncher.Launcher.main(Launcher.java:65) [modlauncher-5.0.0-milestone.4.jar:?] {}

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

-- Head --
Thread: Render thread
Stacktrace:
    at net.minecraft.util.registry.Bootstrap.func_151354_b(Bootstrap.java:34)
    at net.minecraft.client.Minecraft.<init>(Minecraft.java:353)

-- Initialization --
Details:
Stacktrace:
    at net.minecraft.client.main.Main.main(SourceFile:166)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:56)
    at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$399/322830747.call(Unknown Source)
    at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54)
    at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72)
    at cpw.mods.modlauncher.Launcher.run(Launcher.java:81)
    at cpw.mods.modlauncher.Launcher.main(Launcher.java:65)

-- System Details --
Details:
    Minecraft Version: 1.15.2
    Minecraft Version ID: 1.15.2
    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: 756799712 bytes (721 MB) / 1711276032 bytes (1632 MB) up to 2147483648 bytes (2048 MB)
    CPUs: 4
    JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
    Launched Version: 1.15.2-forge-31.1.45
    Backend library: LWJGL version 3.2.2 build 10
    Backend API: NO CONTEXT
    GL Caps: 
    Using VBOs: Yes
    Is Modded: Definitely; Client brand changed to 'forge'
    Type: Client (map_client.txt)
    CPU: <unknown>
    OptiFine Version: OptiFine_1.15.2_HD_U_G1_pre13
    OptiFine Build: 20200401-232147
    Shaders: null
    OpenGlVersion: null
    OpenGlRenderer: null
    OpenGlVendor: null
    CpuCount: 0

23 minutes ago, Triple_craft_2 said:

OptiFine Version: OptiFine_1.15.2_HD_U_G1_pre13

Make sure you read the Optifine changelog for details on the versions of forge it is compatible with.

Currently there is no Optifine that works with forge for 1.15.2.