UE5.1 keeping crash after compiling

Hey guys. Today I find that EVERY time after compiling, UE5.1 will crash. All of my three projects created before meet this problem. And when I create a new project, it seems work propertly. I tried live coding, UnrealBuildTool.exe and the recompile button in Editor, all these methods keeping crash.
Luckily, the compile result is right and when I reopen the Editor, the last compile result works.
I’m confused because even yesterday, they all worked correctly. Does anyone get the same problem?

The track is below:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000000

UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_UnrealEd
UnrealEditor_HotReload
UnrealEditor_HotReload
UnrealEditor_HotReload
UnrealEditor_HotReload
UnrealEditor_HotReload
UnrealEditor_HotReload
UnrealEditor_Core
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

It’s hard to tell, but perhaps you could try tracking down your last changes to your code before the issues started and remove/disable that portion and see if it clears it up and go from there. “Divide and conquer”. I’ve run across this a couple times.

well, i have revert my code to several days before and it donot work. Thou good point, I will keep trying

I found if I inherit ALevelInstance, it will crash. lol