Unreal Engine Issues
Unreal Engine Issues
JsonObjectToUStruct removes _ClassName from input FJsonObject, breaking repeated deserialization
UE - Foundation - Mar 18, 2026FJsonObjectConverter::JsonObjectToUStruct removes _ClassName from nested JSON objects during deserialization. Removing Obj->RemoveField(ObjectClassNameKey) from ConvertScalarJsonValueToFPropertyWit ...
UAbilityTask_SpawnActor::BeginSpawningActor may return true when SpawnedActor contains stale value
UE - Foundation - Mar 15, 2026UAbilityTask_SpawnActor::BeginSpawningActor assumes the incoming AActor*& SpawnedActor parameter is nullptr if no actor was spawned, but it does not initialize the parameter at the start of the func ...
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 - Foundation - 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 - Foundation - 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 ...
Structured log automated decimal number tests fail in languages / cultures that use commas instead of periods
UE - Foundation - Jul 17, 2025The following Localisation Tests in "Engine\Source\Runtime\Core\Tests\Logging\StructuredLogFormatTest.cpp:275" TestLoc(LOCTEXT("Float", " {Float} "), ANSITEXTVIEW(R"(128.25)")); TestLoc(LOCTEXT ...
Crash when using StaticDuplicateObject with mismathced Source and Destination class types
UE - Foundation - Jun 19, 2025Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...
Staging a patch does not copy pak signatures when staging
UE - Foundation - Jun 10, 2025When creating a patch with pak signing enabled the created output folder contains the pak files from the base release but does not contain the .sig files, even if they were enabled when creating the ...
Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level
UE - Foundation - May 15, 2025In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...
InstancedStruct Local Variables do not work
UE - Foundation - May 7, 2025The licensee has noticed that local variables of type InstancedStruct return nullptr. The setup is a verification of the behavior. Class variables work normally. I've tested this behavior on every v ...
Commandlet Exits With Code -1073741819 and Exception FPlatformMisc::RequestExitWithStatus(1, 3, WindowsPlatformCrashContext.EngineUnhandledExceptionFilter)Engine exit requested (reason: Win RequestExit; note: exit was already requested)
UE - Foundation - Apr 9, 2025When a commandlet is run it successfully completes but does not terminate the engine correctly. It appears that multiple requests are made to terminate the engine process these subsequent engine ter ...