问题描述：项目一开始使用UE4.23，后来升级到UE4.24，出现修改蓝图组件属性，甚至UE4原生组件，比如灯光的Light的Channel都会导致UE4崩溃。
解决办法：
1.使用Reload，蓝图修改第一次不会崩溃，第二次依然会崩溃。
2.设置Projecting里的EditorScene为空，重新打开UE4 Editor，目的是保证我们要修改的蓝图，没有场景对象实例依赖或引用目标蓝图，修改蓝图属性正常。
3.比对UE4.25源码，发现是UE4的bug，并且已经在4.25修复，下面是diff文件，通过git合并到4.24源码中。
Engine/Source/Runtime/CoreUObject/Private/UObject/LinkerLoad.cpp | 4 ++--1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/Engine/Source/Runtime/CoreUObject/Private/UObject/LinkerLoad.cpp b/Engine/Source/Runtime/CoreUObject/Private/UObject/LinkerLoad.cpp
index ad31ca8b3be..4808717dc92 100644
--- a/Engine/Source/Runtime/CoreUObject/Private/UObject/LinkerLoad.cpp
+++ b/Engine/Source/Runtime/CoreUObject/Private/UObject/LinkerLoad.cpp
@@ -549,7 +549,7 @@ void FLinkerLoad::PRIVATE_PatchNewObjectIntoExport(UObject* OldObject, UObject*// Detach the old object to make room for the newconst EObjectFlags OldObjectFlags = OldObject->GetFlags();
- OldObject->ClearFlags(RF_NeedLoad|RF_NeedPostLoad);
+ OldObject->ClearFlags(RF_NeedLoad|RF_NeedPostLoad| RF_NeedPostLoadSubobjects);OldObject->SetLinker(nullptr, INDEX_NONE, true);// Copy flags from the old CDO.
@@ -4489,7 +4489,7 @@ UObject* FLinkerLoad::CreateExport( int32 Index ){// For classes that are about to be regenerated, make sure we register them with the linker, so future references to this linker index will be validconst EObjectFlags OldFlags = Export.Object->GetFlags();
- Export.Object->ClearFlags(RF_NeedLoad|RF_NeedPostLoad);
+ Export.Object->ClearFlags(RF_NeedLoad|RF_NeedPostLoad | RF_NeedPostLoadSubobjects);Export.Object->SetLinker( this, Index, false );Export.Object->SetFlags(OldFlags);}
其实就2行代码修改：
//LinkerLoad::PRIVATE_PatchNewObjectIntoExport
OldObject->ClearFlags(RF_NeedLoad|RF_NeedPostLoad);
修改为OldObject->ClearFlags(RF_NeedLoad|RF_NeedPostLoad| RF_NeedPostLoadSubobjects);//UObject* FLinkerLoad::CreateExport( int32 Index )
Export.Object->ClearFlags(RF_NeedLoad|RF_NeedPostLoad);
修改为Export.Object->ClearFlags(RF_NeedLoad|RF_NeedPostLoad | RF_NeedPostLoadSubobjects);