Pressing ESC while on a drag operation makes drag visual to be disappeared and OnDragCancelled not to be called.

UE - Editor - UI Systems - Dec 11, 2018

DragDropOperation is removed when pressing esc button. but this is skipping OnDragCancelled so it can disrupt user's UMG drag operation logic.  ...

DPI Scale Rule set to custom can cause performance issues during design time

UE - Editor - UI Systems - Nov 19, 2018

When setting the DPI Scale Rule to custom and using a named slot the frame rate of the editor will drop while zooming in and out of a widget that uses the widget containing the named slot. ...

DataSmith importer is setting incorrect scale on Actors

OLD - Enterprise - Nov 16, 2018

When importing, DataSmith is assigning a scale on the actors, the option to set the import scale is no longer available in 4.21. ie: a 36" item comes in at 96" This was reported and tested in 4.21 ...

UCanvasPanelSlot::PostEditChangeChainProperty does not call Super function

UE - Editor - UI Systems - Nov 13, 2018

UCanvasPanelSlot::PostEditChangeChainProperty not only does not call its Super function unless the anchor node has been set, but it calls Super:: PostEditChangeProperty instead PostEditChainProperty ...

Instance static mesh instances are reset to zero when moving actor between levels (via move actor to current level)

Tools - Nov 13, 2018

When moving an instance static mesh between sublevels the number of instances being used will be set to zero. This happens when an empty actor is added to the level and then has an instance static m ...

Reset To Defaults in Editor Preferences Graph Editor does not work consistently

Tools - Nov 7, 2018

The Reset to Defaults button in Editor Preferences does not reset all the properties to their default values. Tested in 4.19.2 (CL - 4033788), 4.20.3 (CL - 4369336), 4.21 (CL - 4543149), 4.22 (CL ...

AIController can't properly unpossess character

UE - AI - Nov 5, 2018

There seems to be a bug with the Possess\Unpossess events. Because if you change the last node in "PossessCharacter", which is created in PlayerController(called "PC"), to Unpossess the AI still con ...

Skeletal Mesh rigid body simulation is not being updated with correct bones locations right after Skeletal Mesh is spawned

UE - Simulation - Physics - Nov 5, 2018

When simulating in Editor, the Skeletal Mesh bone locations are not being passed into simulate if the simulation is being toggled the same frame when the Mesh is being set on a Skeletal Mesh compone ...

PressMethod is not called in UButton::RebuildWidget()

UE - Editor - UI Systems - Slate - Nov 5, 2018

The void function UButton::RebuildWidget() does not call PressMethod when rebuilding the widget. Tested  4.19.2 (CL- 4033788), 4.20.3 (CL - 4369336), 4.21 (CL - 4537669), 4.22 (CL - 4531805) ...

Gameplay Tag Query using NoTagMatch expression does not construct DebugString properly

UE - Gameplay - Nov 1, 2018

The code in GameplayTagContainer.cpp has code for generating debug strings representing tag queries. Compare the code in EmitTokens in all other queries to the code in UEditableGameplayTagQueryExpre ...