---- Minecraft Crash Report ----

WARNING: coremods are present:
Contact their authors BEFORE contacting forge

// This is a token for 1 free hug. Redeem at your nearest Mojangsta: [HUG]

Time: 9/7/19 4:04 PM
Description: Initializing game

java.lang.NoClassDefFoundError: net/minecraft/client/renderer/EntityRenderer
at net.minecraftforge.client.ForgeHooksClient.shouldUseVanillaReloadableListener(ForgeHooksClient.java:959)
at net.minecraft.client.resources.SimpleReloadableResourceManager.func_110544_b(SimpleReloadableResourceManager.java:131)
at net.minecraft.client.resources.SimpleReloadableResourceManager.func_110541_a(SimpleReloadableResourceManager.java:112)
at net.minecraft.client.Minecraft.func_110436_a(Minecraft.java:808)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:247)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:378)
at net.minecraft.client.main.Main.main(SourceFile:123)
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.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.renderer.EntityRenderer
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 14 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:521)
at org.spongepowered.asm.mixin.transformer.Proxy.transform(Proxy.java:72)
at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279)
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176)
... 16 more
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: kotlin.Pair
at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.transformMethod(MixinPreProcessorStandard.java:682)
at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.transform(MixinPreProcessorStandard.java:670)
at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.attach(MixinPreProcessorStandard.java:267)
at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.createContextFor(MixinPreProcessorStandard.java:241)
at org.spongepowered.asm.mixin.transformer.MixinInfo.createContextFor(MixinInfo.java:1144)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:267)
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:353)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.apply(MixinTransformer.java:724)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.applyMixins(MixinTransformer.java:703)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:509)
... 19 more
Caused by: java.lang.ClassNotFoundException: kotlin.Pair
... 29 more

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

-- Head --
Thread: Client thread
Stacktrace:
at net.minecraftforge.client.ForgeHooksClient.shouldUseVanillaReloadableListener(ForgeHooksClient.java:959)
at net.minecraft.client.resources.SimpleReloadableResourceManager.func_110544_b(SimpleReloadableResourceManager.java:131)
at net.minecraft.client.resources.SimpleReloadableResourceManager.func_110541_a(SimpleReloadableResourceManager.java:112)
at net.minecraft.client.Minecraft.func_110436_a(Minecraft.java:808)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:247)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:378)
at net.minecraft.client.main.Main.main(SourceFile:123)
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.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.12.2
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: 527982072 bytes (503 MB) / 805306368 bytes (768 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: MCP 9.42 Powered by Forge 14.23.5.2836 5 mods loaded, 5 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

| State | ID            | Version      | Source                        | Signature                                |
|:----- |:------------- |:------------ |:----------------------------- |:---------------------------------------- |
| L     | minecraft     | 1.12.2       | minecraft.jar                 | None                                     |
| L     | mcp           | 9.42         | minecraft.jar                 | None                                     |
| L     | FML           | 8.0.99.99    | forge-1.12.2-14.23.5.2836.jar | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| L     | forge         | 14.23.5.2836 | forge-1.12.2-14.23.5.2836.jar | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| L     | betterportals | 0.2.6        | betterportals-0.2.6.jar       | None                                     |

Loaded coremods (and transformers): 
GL info: ' Vendor: 'Intel' Version: '4.4.0 - Build 20.19.15.4703' Renderer: 'Intel(R) HD Graphics 405'
Launched Version: 1.12.2-forge1.12.2-14.23.5.2836
LWJGL: 2.9.4
OpenGL: Intel(R) HD Graphics 405 GL version 4.4.0 - Build 20.19.15.4703, Intel
GL Caps: Using GL 1.3 multitexturing.

Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Packs: 
Current Language: ~~ERROR~~ NullPointerException: null
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Pentium(R) CPU J3710 @ 1.60GHz

You're missing Forgelin: https://www.curseforge.com/minecraft/mc-mods/betterportals/relations/dependencies?filter-related-dependencies=3

You're also using an old BP version.