Failed to start Minecraft:
java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:210)
        at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:245)
        at org.multimc.EntryPoint.listen(EntryPoint.java:143)
        at org.multimc.EntryPoint.main(EntryPoint.java:34)
Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
        at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
        at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
        ... 8 more
Exiting with -1
进程退出，代码：-1。

把你的java换成这个启动试试
https://ruby.cowtransfer.com/s/b4693c9ebdfc49

这个选择哪个文件打开啊，确实是不会调整java的运行环境

好了搞定了，感谢大佬