Unreal Engine Issues
Unreal Engine Issues
GameplayTask classes that have a BeginSpawningActor function never call the Activate function
UE - AI - Oct 3, 2018A class that inherits from GameplayTask which also has a BeginSpawningActor function will not have its Activate function fired properly. Removing this function causes it to fire properly. Regressio ...
RF_WasLoaded is set to False in PIE for instances of a Blueprint if the Blueprint is recompiled
UE - Gameplay - Blueprint - Apr 5, 2019The RF_WasLoaded flag is set to false for Blueprint instances in PIE if the Blueprint is edited and compiled. This is fixed by saving the level which is a simple workaround but this should be needed ...
Cannot change Collision Profile of BP component instances
UE - Simulation - Physics - Oct 24, 2019BP instances placed in level cannot have their components' collision profiles modified to anything other than default and custom. Note that this did not occur in 4.22 (after applying the separate ...
Niagara system loses source emitters when moving Engine from 4.22 or earlier to 4.23 or later.
UE - Niagara - Nov 29, 2019The following code causes this behavior.// NiagaraSystem.cpp for (FNiagaraEmitterHandle& EmitterHandle : EmitterHandles) { EmitterHandle.ConditionalPostLoad(NiagaraVer); if (!EmitterHandl ...
Problems in skeletal mesh merge
There are a few issues a licensee has found with the skeletal mesh merge operation. See the UDN for more details and the proposed fixes. Note, the issue with the cloth merge is already logged in a ...
bIgnoreAllPressedKeysUntilRelease only applies to keys in the previous mapping
UE - Gameplay - Input - Jun 16, 2022This is because the RebuildControlMappings function only checks this flag when you have a mapping that was already added, we should apply this for any new mappings as well. I'll update the repro s ...
Disabling bLerpUVs in Nanite Settings of Static Mesh causes texture warping in clusters
UE - Rendering - Graphics Features - Nanite - Jan 21, 2025The licensee has identified a potential fix by changing if( Settings.bLerpUVs ) to if( Settings.bLerpUVs || UVIndex == 0 ) On line 389 of NaniteBuilder\Private\Cluster.cpp in UE 5.5 ...
Copy-pasting custom property nodes (ControRig etc.) results in invalid bindings, perf issues
UE - Anim - Rigging - Control Rig - Jul 28, 2025From this UDN: [Link Removed] Suggested fix:Override PostPasteNode to perform the GUID update andAdd validation on load to strip 'invalid' copies that do not correspond to a valid pin input ...
Editor Crashes When Trying to Render Canvas From Blueprint
UE - Graphics Features - Feb 15, 2018This occurs in 4.19p but not in 4.18. Per User: As of current preview, there is no possibility to render in blueprint using canvas, (UCanvas::K2_DrawMaterialTriangle always ends up with assert in ...
Crash upon trying to add a variable to a struct array when the details panel is locked
Tools - Jul 12, 2018Attempting to add a new element to a struct array through the details panel when the panel is locked results in a crash. Regression?: No This issue did not occur exactly the same way in 4.18, but t ...