Unreal Engine Issues
Unreal Engine Issues
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 ...
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 adding custom CameraComponent to BP with CameraSettings hidden
UE - Gameplay - Components - Oct 8, 2015Using the HideCategories = (CameraSettings) specifier inside a custom CameraComponent class will cause the editor to crash when the component is added to a blueprint. Restarting the editor will sho ...
Crash when Child Actor Component overlaps Parent static mesh inside of the blueprint editor
UE - Gameplay - Sep 21, 2015Crash when Child Actor Component, that is set to Destroy Other Actor on overlap, overlaps Parent static mesh inside of the blueprint editor Crash Reporter: [Link Removed] ...
Adding widget to viewport on code overlap event causes the editor to crash when opening child blueprint
UE - Editor - UI Systems - Oct 30, 2015Setting a UMG widget to be added to viewport when a volume is overlapped though code and creating a blueprint of this class causes the editor to crash when the blueprint is opened if the BP has a st ...
Changing levels after setting an images material to a dynamic material with a widget blueprint that has been added to the viewport within a HUD blueprint will cause a crash
UE - Editor - UI Systems - Sep 21, 2015A crash occurs if the following conditions are metSetting an image widget to a dynamic materialAdding the widget blueprint to the viewport from within a HUD blueprintChanging levels ...