Unreal Engine Issues
Unreal Engine Issues
BlendSpace DeltaTimeRecord.Delta can incorrectly be set to zero
UE - Runtime - Animation - Apr 19, 2024It's possible for blendspaces to end up with an invalid delta time record because of how UBlendSpace::TickAssetPlayer modifies the time record. This only seems to happen with specific settings:Axis ...
Crash when changing a Play Node's "Sequence" to a Montage
OLD - Anim - Jan 20, 2016I understand that this is not something you're intended to be able to do (Montages aren't used this way), but we should bar the user from inserting a montage into this variable slot. Crash occurs w ...
SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly
UE - Gameplay - Jun 4, 2024The 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 ...
Collision profiles are reset when blueprint is loaded
UE - Gameplay - Jan 6, 2025In UE 5.5 (and earlier versions), FCollisionResponse::operator== has incorrect behavior where it will detect that two collision response containers are identical if they have the same number of entr ...
Dangling pointer + mem corruption related to OwnerLastRenderTimePtr
UE - Engine Scaling - Streaming - Mar 16, 2026We've been seeing asserts and crashes related to OwnerLastRenderTimePtr. We've traced this to the mentioned pointer ending up dangling after using UActorComponent::Rename() on primitive components t ...
FString.Mid doesn't react appropriately when given negative values for the Count variable
UE - Foundation - Core - Jul 16, 2015If you use a 5 character string (hello) to call the Mid function and provide 0 for start, -1 for count, it'll give you the entire string. This should either return an assert or treat all negatives a ...
Warnings after Launching onto Mobile
UE - Platform - Mobile - Oct 27, 2016Launching onto android causes 1-3 warnings in the output log. I ensured that the mobile device was connected to Epic-Secure. LogTcpMessaging:Warning: Discovered node '00529FEE320A011C0032002F8B3E2F4 ...
AreaNavModifiers generated by SplineNavModifierComponent have the component-to-world transform incorrectly applied twice
UE - Runtime - Character - Aug 15, 2025USplineNavModifierComponent was made available in UE 5.4. It generates several FAreaNavModifier instances covering a region with a certain thickness around a USplineComponent, and worked correctly u ...
Available network bandwidth is too low for uncapped but slow frame rates
UE - Framework - Networking - Sep 24, 2020The networking system has a max frame rate of 120hz by default. Inside UNetConnection::Tick it computes an estimated bandwidth by using that max frame rate, the engine's max frame rate, and the actu ...
Look at Android GetTimeStamp local file handling
UE - Platform - Mobile - Systems - May 29, 2020Only files in UFS or NonUFS manifest that are local are returning a non-minvalue timestamp. While this is expected it is causing issues with logging file handling. See: https://udn.unrealengine.co ...