搭建环境都是successful，导入eclipse后跑client发现跑不动

[17:26:39] [main/INFO] [GradleStart]: Extra: []
Exception in thread "main" 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.minecraftforge.gradle.GradleForgeHacks.searchCoremods(GradleForgeHacks.java:85)
    at net.minecraftforge.gradle.GradleStartCommon.launch(GradleStartCommon.java:86)
    at GradleStart.main(GradleStart.java:25)
用的jre1.8

你确认是java8？
Exception in thread "main" java.lang.RuntimeException: java.lang.ClassCastException: jdk.internal.loader.ClassLoaders$AppClassLoader (in module: java.base) cannot be cast to java.net.URLClassLoader (in module: java.base)
Java9之后，应用程序和扩展类都不再是 java.net.URLClassLoader 的实例
肯定版本不对

已解决，感谢！