Editor can crash while performing a Hot Reload after a custom UClass class is added to the project

Performing a Hot Reload after creating a custom UClass class can result in a crash.

This was reported on Linux, but reproduced on Windows. Additional testing will be done on Linux to confirm the issue there as well.

1. Create a new Basic Code project.
2. Build the project.
3. Open the project in the Editor.
4. Add a new class to the project derived from Object.
5. Close the Editor.
6. Change the parent class of the new class from UObject to UClass.
   • There should be nothing in this class other than a GENERATED_BODY() macro.
7. Build the project.
8. Open the project in the Editor.
9. Click the "Compile" button.
   • This step may need to be repeated a few times.

RESULT:
The Editor crashes due an assertion: Assertion failed: ClassAddReferencedObjects != 0

EXPECTED:
The Hot Reload completes successfully and the Editor does not crash.

Assertion failed: ClassAddReferencedObjects != 0 [Link Removed] [Line: 2193]

UE4Editor_Core!FWindowsErrorOutputDevice::Serialize() [d:\main-builds\stream\engine\source\runtime\core\private\windows\windowserroroutputdevice.cpp:79]
UE4Editor_Core!FOutputDevice::LogfImpl() [d:\main-builds\stream\engine\source\runtime\core\private\misc\outputdevice.cpp:71]
UE4Editor_Core!FDebug::AssertFailed() [d:\main-builds\stream\engine\source\runtime\core\private\misc\assertionmacros.cpp:446]
UE4Editor_Core!FDebug::CheckVerifyFailedImpl() [d:\main-builds\stream\engine\source\runtime\core\private\misc\assertionmacros.cpp:424]
UE4Editor_CoreUObject!UClass::AssembleReferenceTokenStream() [d:\main-builds\stream\engine\source\runtime\coreuobject\private\uobject\garbagecollection.cpp:2193]
UE4Editor_CoreUObject!UClass::AssembleReferenceTokenStreams() [d:\main-builds\stream\engine\source\runtime\coreuobject\private\uobject\class.cpp:4373]
UE4Editor_HotReload!FHotReloadModule::ReinstanceClasses() [d:\main-builds\stream\engine\source\developer\hotreload\private\hotreload.cpp:1228]
UE4Editor_HotReload!TBaseRawMethodDelegateInstance<0,FHotReloadModule,void __cdecl(void)>::ExecuteIfSafe() [d:\main-builds\stream\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:518]
UE4Editor_CoreUObject!TBaseMulticastDelegate<void>::Broadcast() [d:\main-builds\stream\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:977]
UE4Editor_CoreUObject!UClassReplaceHotReloadClasses() [d:\main-builds\stream\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:860]
UE4Editor_CoreUObject!ProcessNewlyLoadedUObjects() [d:\main-builds\stream\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:1017]
UE4Editor_CoreUObject!TBaseStaticDelegateInstance<void __cdecl(FName,bool)>::ExecuteIfSafe() [d:\main-builds\stream\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:813]
UE4Editor_Core!TBaseMulticastDelegate<void,FName,bool>::Broadcast() [d:\main-builds\stream\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:977]
UE4Editor_Core!FModuleManager::LoadModuleWithFailureReason() [d:\main-builds\stream\engine\source\runtime\core\private\modules\modulemanager.cpp:529]
UE4Editor_Core!FModuleManager::LoadModule() [d:\main-builds\stream\engine\source\runtime\core\private\modules\modulemanager.cpp:367]
UE4Editor_HotReload!FHotReloadModule::DoHotReloadInternal() [d:\main-builds\stream\engine\source\developer\hotreload\private\hotreload.cpp:789]
UE4Editor_HotReload!UE4Function_Private::TFunctionRefCaller<<lambda_9c48366a887b61ded2fa445a677e9fc1>,void __cdecl(TMap<FName,FString,FDefaultSetAllocator,TDefaultMapHashableKeyFuncs<FName,FString,0> > const &,bool,enum ECompilationResult::Type)>::Call() [d:\main-builds\stream\engine\source\runtime\core\public\templates\function.h:487]
UE4Editor_HotReload!FHotReloadModule::CheckForFinishedModuleDLLCompile() [d:\main-builds\stream\engine\source\developer\hotreload\private\hotreload.cpp:1853]
UE4Editor_HotReload!FHotReloadModule::Tick() [d:\main-builds\stream\engine\source\developer\hotreload\private\hotreload.cpp:1421]
UE4Editor_Core!FTicker::Tick() [d:\main-builds\stream\engine\source\runtime\core\private\containers\ticker.cpp:95]
UE4Editor!FEngineLoop::Tick() [d:\main-builds\stream\engine\source\runtime\launch\private\launchengineloop.cpp:4277]
UE4Editor!GuardedMain() [d:\main-builds\stream\engine\source\runtime\launch\private\launch.cpp:173]
UE4Editor!GuardedMainWrapper() [d:\main-builds\stream\engine\source\runtime\launch\private\windows\launchwindows.cpp:145]
UE4Editor!WinMain() [d:\main-builds\stream\engine\source\runtime\launch\private\windows\launchwindows.cpp:275]
UE4Editor!__scrt_common_main_seh() [d:\agent\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

Fix UE-51650

i have this problem UE4CC-Windows-58DC12AF4B97F057BD108FBFF569B2E9_0000

I am not able to find world outliner how to enable it?

Error UE5 5.0.3

Undefined sysmbol: typeinfo for AActor when cross-compile linux dedicated server on windows

How can i modify the param name in EQS node

Delay nodes occasionally don't fire the "Completed" output in a nativized build

An error occurred while trying to generate project files !?

Bonjour j'ai un petit problème c'est que je ne vois plus l'onglet "scability" pour changer les graphismes de uefn et j'ai pas trouvé l'option pour le faire revenir ?

Bullet replication problem. The players sees each other but does not see the bullet