Hi,this its my crash report:
---- Minecraft Crash Report ----

WARNING: coremods are present:
TheBetweenlandsLoadingPlugin (TheBetweenlands-3.9.0-core.jar)
ShoulderPlugin (ShoulderSurfing-1.12.2-1.15.1.jar)
Quark Plugin (Quark-r1.6-179.jar)
Contact their authors BEFORE contacting forge

// Shall we play a game?

Time: 11/13/23 1:13 PM
Description: There was a severe problem during mod loading that has caused the game to fail

net.minecraftforge.fml.common.LoaderException: java.lang.ClassNotFoundException: mezz.jei.startup.ProxyCommonClient
at net.minecraftforge.fml.common.ProxyInjector.inject(ProxyInjector.java:102)
at net.minecraftforge.fml.common.FMLModContainer.constructMod(FMLModContainer.java:611)
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 com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
at com.google.common.eventbus.EventBus.post(EventBus.java:217)
at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219)
at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
at com.google.common.eventbus.EventBus.post(EventBus.java:217)
at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136)
at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:595)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:232)
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: mezz.jei.startup.ProxyCommonClient
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)
at net.minecraftforge.fml.common.ModClassLoader.loadClass(ModClassLoader.java:75)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at net.minecraftforge.fml.common.ProxyInjector.inject(ProxyInjector.java:85)
... 37 more
Caused by: java.lang.IllegalArgumentException
at org.objectweb.asm.ClassReader.(ClassReader.java:185)
at org.objectweb.asm.ClassReader.(ClassReader.java:168)
at net.minecraftforge.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.findAndMergeSuperMaps(FMLDeobfuscatingRemapper.java:425)
at net.minecraftforge.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.getMethodMap(FMLDeobfuscatingRemapper.java:402)
at net.minecraftforge.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.mapMethodName(FMLDeobfuscatingRemapper.java:349)
at org.objectweb.asm.commons.RemappingMethodAdapter.doVisitMethodInsn(RemappingMethodAdapter.java:156)
at org.objectweb.asm.commons.RemappingMethodAdapter.visitMethodInsn(RemappingMethodAdapter.java:143)
at org.objectweb.asm.ClassReader.readCode(ClassReader.java:1496)
at org.objectweb.asm.ClassReader.readMethod(ClassReader.java:1032)
at org.objectweb.asm.ClassReader.accept(ClassReader.java:708)
at org.objectweb.asm.ClassReader.accept(ClassReader.java:521)
at net.minecraftforge.fml.common.asm.transformers.DeobfuscationTransformer.transform(DeobfuscationTransformer.java:76)
at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279)
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176)
... 43 more

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

-- System Details --
Details:
Minecraft Version: 1.12.2
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 547403240 bytes (522 MB) / 805306368 bytes (768 MB) up to 4294967296 bytes (4096 MB)
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
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP 9.42 Powered by Forge 14.23.5.2859 Optifine OptiFine_1.12.2_HD_U_G5 10 mods loaded, 10 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                                |
|:----- |:--------------- |:------------ |:----------------------------------- |:---------------------------------------- |
| LC    | minecraft       | 1.12.2       | minecraft.jar                       | None                                     |
| LC    | mcp             | 9.42         | minecraft.jar                       | None                                     |
| LC    | FML             | 8.0.99.99    | forge-1.12.2-14.23.5.2859.jar       | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| LC    | forge           | 14.23.5.2859 | forge-1.12.2-14.23.5.2859.jar       | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| LE    | jei             | 4.16.1.302   | jei_1.12.2-4.16.1.302.jar           | None                                     |
| L     | quark           | r1.6-179     | Quark-r1.6-179.jar                  | None                                     |
| L     | autoreglib      | 1.3-32       | AutoRegLib-1.3-32.jar               | None                                     |
| L     | mobends         | 0.24         | mobends-0.24_for_MC-1.12.jar        | None                                     |
| L     | shouldersurfing | 1.16         | ShoulderSurfing-1.12.2-1.15.1.jar   | None                                     |
| L     | thebetweenlands | 3.9.0        | TheBetweenlands-3.9.0-universal.jar | None                                     |

Loaded coremods (and transformers): 

TheBetweenlandsLoadingPlugin (TheBetweenlands-3.9.0-core.jar)
thebetweenlands.core.TheBetweenlandsClassTransformer
ShoulderPlugin (ShoulderSurfing-1.12.2-1.15.1.jar)
com.teamderpy.shouldersurfing.asm.ShoulderTransformations
Quark Plugin (Quark-r1.6-179.jar)
vazkii.quark.base.asm.ClassTransformer
GL info: ' Vendor: 'Intel' Version: '4.3.0 - Build 10.18.15.4256' Renderer: 'Intel(R) HD Graphics 4400'
OptiFine Version: OptiFine_1.12.2_HD_U_G5
OptiFine Build: 20210124-142939
Render Distance Chunks: 12
Mipmaps: 4
Anisotropic Filtering: 1
Antialiasing: 0
Multitexture: false
Shaders: (internal)
OpenGlVersion: 4.3.0 - Build 10.18.15.4256
OpenGlRenderer: Intel(R) HD Graphics 4400
OpenGlVendor: Intel
CpuCount: 4

That's a crash with JEI, not Betweenlands.