HELP:The game crashed whilst fml will not run in demo mode Error: java.lang.RuntimeException Ending code：-1

how to deal it? 

---- Minecraft Crash Report ----
// I bet Cylons wouldn't have this problem.

Time: 1/24/22 10:16 AM
Description: FML will not run in demo mode

java.lang.RuntimeException
    at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:225)
    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)

A detailed walkthrough of the error, its code path and all known details is as follows:
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-- 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: 708405712 bytes (675 MB) / 842006528 bytes (803 MB) up to 3817865216 bytes (3641 MB)
    JVM Flags: 3 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx4096m -Xms256m
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: 
    Loaded coremods (and transformers): 
    GL info: ' Vendor: 'NVIDIA Corporation' Version: '4.6.0 NVIDIA 462.42' Renderer: 'GeForce GTX 1050 Ti/PCIe/SSE2'