---- Hello Minecraft! Crash Report ----
  Version: 3.3.188
  Time: 2021-08-02 11:26:13
  Thread: Thread[JavaFX Application Thread,5,main]

  Content:
    java.lang.NullPointerException
        at java.util.concurrent.CompletableFuture.completeExceptionally(Unknown Source)
        at org.jackhuang.hmcl.game.LauncherHelper$2.lambda$onStop$0(LauncherHelper.java:491)
        at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
        at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
        at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at com.sun.glass.ui.win.WinApplication.lambda$null$4(WinApplication.java:186)
        at java.lang.Thread.run(Unknown Source)


-- System Details --
  Operating System: Windows 10 10.0
  Java Version: 1.8.0_261, Oracle Corporation
  Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
  JVM Max Memory: 259522560
  JVM Total Memory: 60919808
  JVM Free Memory: 21258600

看看有没有安装最新版的Java

看着像是内存设置问题，楼主内存设置正确吗

现在好了，是Java位数的问题