Unreal Engine Issues

SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly

The description of SpringArmComponent's "Use Camera Lag Substepping" option says "sub-step camera damping so that it handles fluctuating frame rates well". However, as noted and explained by a licen ...

Calling SetupAttachment/AttachToComponent with 'this' as the parent inside a USceneComponent subtype's C++ ctor for nested component subobjects will result in all instances of the nested default subobject trying to attach to the CDO at registration time.

This occurs because the 'AttachParent' property is a UPROPERTY, and as a result when we create a new instance of a USceneComponent subtype, any USceneComponent subtypes it owns are treated as instan ...

Action event in the blueprint graph leads to state dirty.

BP state get dirty if the BP graph have action input event. Regression: Yes, it is not reproduced in 4.16.3 This issue is not related to Blueprint Compilation Manager. ...

GAS: RemoveReplicatedLooseGameplayTag on unadded tag causes it to be replicated

A UDN user found that calling AbilitySystemComponent->RemoveReplicatedLooseGameplayTag(TagToRemove); while the gameplay tag was not in the TagMap, will create an entry for it with count 0, see ...

Pasting custom data floats from a text editor into a instanced static mesh component crashes the editor

When an instanced static mesh component with a material using a PerInstanceCustomData node has its data floats pasted in, the editor crashes with an "Array index out of bounds" error. The licensee w ...

[CrashReport] Crash trying to destroy an uber graph frame because the RawPointer is still set

This is a trending crash in the 4.17 Preview. Users have not provided any descriptions of their actions when the crash occurred. Source Context 2408 uint8 *Data = (uint8*)Dest; 2409 ...

FMediaFoundationMovieStreamer::Init() returns true even if the movie could not open.

Regression: "Play particle effect" anim notifies are not seen in the editor playing level sequence/matinee when Attached is set to false

Not Attached particle system is not seen in the viewport of the editor. This particle will be seen normally when PIE.  Regression? Yes. This issue is not reproduced in 4.17 version. You can simply ...

Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables

Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables. "Error Internal compiler error inside Creat ...

Destructible attached with a Physics Constraint ignores Start Awake on play

Destructible attached with a Physics Constraint ignores Start Awake on play The Destructible component is set to simulate physics, but on play physics is not simulated unless the destructible is to ...