Unreal Engine Issues
Unreal Engine Issues
FMetadata: References to invalid\destructed objects can accumulate in the ObjectMetaDataMap array
UE - Core - Systems - Oct 7, 2026Customers are reporting that the package metadata can end up referencing to non-existing assets or other assets. This causing validation errors in the editor and also generates warnings during the ...
FDebug::EnsureFailed will only broadcast OnHandleSystemEnsure 4 times.
UE - Core - Systems - Oct 5, 2026A licensee is reporting that OnHandleSystemEnsure will only be broadcasted for the first 4 ensures in the life of the process. This is hardcoded with MaxPreviousErrorsToTrack. The licensee is using ...
TMap where key is an FString: initializer list will accept bad MakeTuple
UE - Core - Systems - Sep 2, 2026POST LINK: https://forums.unrealengine.com/t/tmap-where-key-is-an-fstring-initializer-list-will-accept-bad-maketuple/2747443 POST BODY:Summary A TMap where the key is an FString can be created lik ...
Crash in GC - FSharedStruct reachability race condition
UE - Core - Systems - Jul 13, 2026This Jira was created from the linked EPS case: =============================================== This issue is caused by FSharedStruct batching reachability requests to the same underlying FInstan ...
Regarding TObjectPtr performance regression
UE - Core - Systems - Jul 13, 2026This is from the linked EPS case: ============================== When 5.0 first introduced TObjectPtr, the guidance was that it would compile down to raw pointer access in Shipping builds to ensu ...
JsonObjectToUStruct removes _ClassName from input FJsonObject, breaking repeated deserialization
UE - Core - Systems - Mar 18, 2026FJsonObjectConverter::JsonObjectToUStruct removes _ClassName from nested JSON objects during deserialization. Removing Obj->RemoveField(ObjectClassNameKey) from ConvertScalarJsonValueToFPropertyWit ...
Cooker is asserting in Class.h on UE 5.7.1
UE - Core - Systems - Dec 18, 2025From the linked EPS case: ---------------------------- In UE 5.7 there were some changes to how Enum member names are stored. This change introduces an assert when cooking using the Editor Debug e ...
Content is Missing from Cook and indeterminism: StaticMeshComponents in Blueprints that copy data into themselves from StaticMesh have indeterminism due to StaticMesh not yet finished loading, postloading, or building
UE - Core - Systems - Nov 12, 2025Content is Missing from Cook warnings are warnings reported at the end of cook phase of a project's data build. They report that data used by a cooked package will not be available at runtime. This ...
Property "GameFeatureData.PrimaryAssetTypesToScan.Directories" should be tagged with "ForceShowPluginContent"
UE - Core - Systems - Oct 11, 2025When using a Game Feature Plugin, one of the settings available in the "GameFeatureData" DataAsset (class UGameFeatureData) is "PrimaryAssetTypesToScan", which is an array of FPrimaryAssetTypeInfo s ...
Cook non-determinism when serializing UObject pointers pointing to garbage
UE - Core - Systems - Aug 25, 2025There's a cook determinism issue in the way UObject unversioned serialization handles UObject pointers pointing to garbage. Depending on GC timing, it can either be skipped (as a property matching C ...