Unreal Engine Issues

Regression: Several project settings, especially from built-in Plugins, are being silently erased when previously they were not, which is perceived as a bug

In UE's Project Settings, some pages are saved automatically to the project's "Config/Default<CATEGORY>.ini" file (meant to be version-controlled) on every change. Other pages have buttons "Set as D ...

Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...

Nanite Instanced Static Meshes lost selection outlines in UE5.5

Nanite ISMs lost selection outlines in UE5.5 Actors having an ISM component which uses a static mesh with nanite do not get a selection outline when selected in the editor. Having Nanite is essentia ...

Calling UMoverComponent::IsModifierActiveOrQueued() immediately after calling UMoverComponent::K2_QueueMovementModifier() will return false

Calling UMoverComponent::IsModifierActiveOrQueued() immediately after calling UMoverComponent::K2_QueueMovementModifier() will return false. Checking the code, IsModifierActiveOrQueue() calls FindMo ...

Crashes when attempting to use an Instanced Struct inside Control Rig / Rig VM

Currently, the Control Rig Editor allows the user to use the "Instanced Struct" type, for example for a variable or function input/output. However, this type does not seem to be properly supported ( ...

FJsonObjectConverter::ExportCallback_WriteISO8601Dates allows for writing FDateTime that does not have ticks

Context: `FJsonObjectConverter` is a built-in UE class that makes it easy to convert JSON objects to and from UStructs, including `FDateTime`, which implements a date and time. Problem: An uniniti ...

Crash in right click menu to edit reduce tolerance value

WindDirectionalSourceComponent.h has a meta edit condition that, by referencing an undefined property (bSimulatePhysics), throws an error

WindDirectionalSourceComponent.h has a meta edit condition that, by referencing an undefined class property (bSimulatePhysics), throws an error in the logs: LogEditCondition: Error: EditCondition pa ...

FSubobjectData::SetupAttachment() receives SocketName as a parameter but ignores it.

When using the Subobject Data Subsystem in C++, method FSubobjectData::SetupAttachment() can be used to help attaching a component to a parent at a given socket. This function receives SocketName as ...

Sequence with restore state set is causing a "Fatal world leaks detected" crash

We recently had a few occurrences of crashes caused by a "Fatal world leaks detected" error when unloading a level (in a packaged game and in editor). I tracked down what was keeping a references t ...