Unreal Engine Issues

Loading error for editor only BlueprintNativeEvent functions

The editor-only function in the native parent class is not compiled in the game module, which is why we're getting this error. The Blueprint compiler should follow suit during cooking and not genera ...

Setting a struct bool property (bitfield) to itself writes the wrong value

There's an issue when assigning a bitfield bool to a native bool in Blueprints. Currently, the engine erroneously treats the memory for a local bool as a uint8 bitfield, which is undefined behavior. ...

ULevelSequence trying to duplicate a REINST_ class when creating new custom binding in ConvertOldSpawnables()

The assert that we're hitting is:Cannot replace existing object of a different class.  New Object: /Engine/Transient.REINST_BPC_NPC_VFX_C_230 /Game/Maps/[REDACTED]/Levels/[REDACTED]/LevelSequence/ ...

TInstancedStruct used in native actor class loses reference to Instanced UObject after BP recompilation

When a TInstancedStruct contains a UObject marked with EditInlineNew and DefaultToInstanced, the reference is lost after compiling the Blueprint but only when the struct is part of a native Actor cl ...

Blueprint compiler doesn't always initialize struct consts correctly

Blueprints currently don't support unsigned 64 bit ints, but they do support signed 64 bits. If a Blueprint uses a native struct variable that contains a uint64 property, it incorrectly assigns that ...

Ensure failing when compiling Macro Library blueprints

Editor crash after reverting a Blueprint asset in source control

Added context from dev support ticket:The crash occurs because FDelegateProperty::Serialize accesses a dangling SignatureFunction pointer. Given that its derefencing dangling pointers the specifi ...

No warnings or errors if a UEnum has Bitflags metadata, but no Flags flag.

The problem here isn't obvious: the native enum, EAnotherEnum, is missing the Flags flag for the UEnum. As a result, K2Node_GetEnumeratorNameAsString returns the max enum when it gets a combined fla ...

Bitmask ints can't be converted to strings

While we do have an auto cast function that handles an int to string conversion, bitmask ints use a "bitmask" subcategory which thwarts are ability to find the cast function. ...

K2Node_GetEnumeratorName doesn't support bitmasks

This is almost identical to [Link Removed]. The difference is that we need a variant of UEnum::GetNameByValue that supports bitmasks. We'll likely have to run this by Core. ...