Unreal Engine Issues
Unreal Engine Issues
Translucent User Interface materials do not have a thumbnail preview
Tools - Feb 15, 2018Translucent User Interface materials do not have a thumbnail preview. I do not see this issue with Translucent Surface materials. REGRESSION: No, this issue also occurs as far back as 4.17.2 ...
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 - 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 ...
Crash while unloading a streaming level while spawned decals exist in the unloaded level
UE - Graphics Features - Aug 18, 2017When unloading a level containing a decal that is using a dynamic material instance the editor will crash. ...
Editor crash when a Breakpoint is added to a Widget's Tick function
UE - Editor - UI Systems - Aug 18, 2017Editor crashes when a widget's tick contains a breakpoint at a print string node. Based on 4.16 warning message, this appears to be caused by the text attempting to draw when no draw buffer is avai ...