UPDATE!
We have just released Preview 4 for 4.21! Thank you for your continued help in testing the 4.21 build before its official release. As a reminder, the Preview builds are for testing only, and should not be used for the active development of your project.
For a list of known issues affecting this latest preview, please follow the links provided on the first post in this thread.
Fixed in Preview 4
Fixed! UE-60171 Crash Occurs When Importing a .ABC File as Skeletal Mesh Into Project That Already Contains Asset’s Materials
Fixed! UE-51935 [CrashReport] UE4Editor_Engine!FSkeletalMeshObject::UpdateMinDesiredLODLevel() [skeletalrender.cpp:81]
Fixed! UE-59914 Editor freezes after reimporting alembic asset
Fixed! UE-61761 Importing an Alembic File with “Skip Empty Frames at Start of Alembic Sequence” Enabled Causes Crash
Fixed! UE-62036 Merge Actors tool leads to crash when the selected list is not matching current existing objects due to construction script.
Fixed! UE-62176 Regression: Importing an Alembic File with Geometry cache or Skeletal leads to crash.
Fixed! UE-64886 LODTo Frame Skip Map isn’t causing asset to skip frames
Fixed! UE-64873 ThirdPerson AnimBP arm not affected by Fake Velocity as expected
Fixed! UE-64845 QAGame Get Transition Crossfade Duration Node to Blend Result setup does not produce expected result
Fixed! UE-62337 Alembic Problem - Missing keys in animations when selecting time range
Fixed! UE-61429 Assert importing an ABC as GeomCache
Fixed! UE-63401 Cant save HLODs for an unsaved level & opening mesh causes assert/crash
Fixed! UE-65832 Crash when adding invalid preset chain
Fixed! UE-64622 TestEqual(TCHAR*, TCHAR*) function is testing pointer equality instead of values
Fixed! UE-64484 Garbage is not collected increases during CompileAllBlueprints test
Fixed! UE-65620 Cooked game crashes when launching with -memoryprofiler argument in the command line
Fixed! UE-65572 Engine - Ensure GIsRequestingExit is set before broading termination delegate in FWindowsPlatformMisc::RequestExit
Fixed! UE-63571 Cook-on-the-fly generates corrupt materials
Fixed! UE-65430 Missing Receipt’ error after disabling plugin in binary build and repackaging
Fixed! UE-65286 Unable to GenerateProjectFiles with multiple client targets
Fixed! UE-65278 Binary editor and projects compile shaders during first open
Fixed! UE-65771 Add ShowdownDemo to the Wait to Build Launcher Samples Mac job
Fixed! UE-65432 GitHub 5180 : Fix wrong .natvis file path in generated Visual Studio solution
Fixed! UE-65702 Remote Building for iOS with Nativization fails with “ERROR: Precompiled rules assembly ‘…QAGame_4.21/Intermediate/Plugins/NativizedAssets/IOS/Game/Intermediate/Build/BuildRules/NativizedAssetsModuleRules.dll’ does not exist.”
Fixed! UE-65617 GitHub 5200 : Log file path issue
Fixed! UE-65588 New plugins include developer modules by default
Fixed! UE-65539 ShooterGame build from the launcher does not include client target
Fixed! UE-65006 Packaging failed with disabled plugin
Fixed! UE-65413 Match 3 - Edges of screen are cut off during gameplay
Fixed! UE-65426 [ActionRPG] Spamming potion button decreases potion count without consuming them
Fixed! UE-65235 ActionRPG has For Distribution enabled in Packaging Settings
Fixed! UE-65562 ActionRPG - Can’t find file ‘/Script/EnvironmentQueryEditor’
Fixed! UE-65559 ARPG Linear Color Curve Warning
Fixed! UE-50730 SunTemple quality is low on iOS tablets
Fixed! UE-61752 ARPG trail emitters render with solid blue texture on Mali GPU
Fixed! UE-61751 ARPG roll no longer has a trail emitter
Fixed! UE-61323 Having an empty slot between weapons only lets player use top weapon in ActionRPG
Fixed! UE-60454 ARPG - Removed unused assets
Fixed! UE-65783 Content Examples MathHall - Error: T_1x1_Grid T_1x1_Grid Same lighting guid
Fixed! UE-65715 Deprecated DOF Warning When entering Post Processing Volumes
Fixed! UE-65861 Content Examples - Lighting needs to be rebuilt in Niagara level
Fixed! UE-65449 [ActionRPG] Weapon swapping does not update icons in HUD
Fixed! UE-65456 Crash when changing the UDP Messaging Tunnel Unicast Endpoint address
Fixed! UE-65634 TP_MultiUserViewer misc issues
Fixed! UE-65551 Duplicate nDisplay template project
Fixed! UE-65646 FlakesAccess shader doesn’t compile on
Fixed! UE-65442 Crash running a game with Variant set - Assertion failed: RecursionNotAllowed.Increment() == 1
Fixed! UE-64661 Blackmagic sync output hiccups sometimes
Fixed! UE-65576 STUN and TURN servers needs start scripts for first time users
Fixed! UE-65014 Multi-User Template Project holds at 95% for a very long time
Fixed! UE-65611 Crash indexing Blueprints- LongPackageNameToFilename failed to convert ‘None’. Path does not map to any roots.
Fixed! UE-65586 //UE4/Release-4.21 failing to compile - error in KismetReinstanceUtilities.cpp
Fixed! UE-63310 Sky box renders as black when packaged with nativization enabled.
Fixed! UE-63834 [CrashReport] UE4Editor_Kismet!FBlueprintCompilationManagerImpl::ReinstanceBatch
Fixed! UE-64888 Packages with Inclusive/Exclusive Nativization crashing referencing AsyncLoading.cpp
Fixed! UE-65759 (Regression) Risk of PostLoad() assert crash in all cooked, nativized builds with async load thread enabled.
Fixed! UE-65389 Ensure reopening map after changing a blueprint’s component to a derived class and keeping the same name
Fixed! UE-64576 Pawn Velocity dramatically different on server and client with Client Authoritative Position
Fixed! UE-64544 [CrashReport] UE4Editor_Engine!AGameSession::RegisterPlayer() [gamesession.cpp:235]
Fixed! UE-64431 When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable
Fixed! UE-62952 “Enabled per poly collision” under “Support compute skincache” is ON causes a crash at runtime
Fixed! UE-61399 Objects get stuck when hit location is same as start ray location
Fixed! UE-62714 Physics replication is not working correctly and clients receive different results
Fixed! UE-62345 Replicated Movement doesn’t replicate itself to all clients on Dedicated Server
Fixed! UE-65390 CrashReportClient callstack has cut off text on Linux
Fixed! UE-64312 projects crash when alt-tabbing on Linux
Fixed! UE-64798 Crash when Fracturing Mesh - Assertion failed: (Index >= 0) & (Index < ArrayNum)
Fixed! UE-58866 Tooltips are not readable on Linux with and NVidia drivers
Fixed! UE-62199 AArch64 server crashes when opening
Fixed! UE-65567 Linux: initial movie is not scaled full screen
Fixed! UE-65656 Cannot rotate camera while shooting if mouse cursor is over the edge of Mac window
Fixed! UE-65343 Skeletal Mesh with more than 75 bones crashes Mobile Preview
Fixed! UE-65311 SunTemple - package crashes on device when initializing on iPhone 6+
Fixed! UE-65464 Typo in Support Software Occlusion Culling tooltip in Project Settings
Fixed! UE-65622 CLONE - Add detection and device profiles for iPhone XS / XS Max / SR
Fixed! UE-65540 TextureFormats list in GameActivity for PVRTC has comma in wrong place
Fixed! UE-61970 Templates fail to package for Android - AAPT: error: resource android
Fixed! UE-63725 Blueprint Projects can’t make APK without compiled .so Error when packaging for Android with any Plugin Disabled
Fixed! UE-63682 There is no force feedback on iPhone 6S devices
Fixed! UE-65016 OpenGLES API deprecated warnings when packaging AR Samples
Fixed! UE-64536 iOSClient is not built. Just creates {OS}Client target.
Fixed! UE-65647 Crash starting Strategy Game in OpenGLShaders.cpp
Fixed! UE-65022 template project crashes on Android
Fixed! UE-65459 Remote Building for iOS Fails During Build Step: “File for download ‘UBT-UE65273Verif-IOS-Development_Remote.txt’ is not under the engine or project directory”
Fixed! UE-65860 tvOS crash on launch: “this class is not key value coding-compliant for the key”
Fixed! UE-63540 Black bars seen when launching app on iPhone X packaged with DebugGame build configuration
Fixed! UE-40545 TVOS images are throwing errors when attempting to deploy to iTunes Connect
Fixed! UE-65417 iPhone X devices do not use all available screen space causing black bars in game
Fixed! UE-65825 Rect lights emit backwards light to volumetric lightmaps from the rect backside.
Fixed! UE-65513 Crash when switching to windowed mode in OpenGL with Media Textures
Fixed! UE-65458 Texture Painting in - throws an ensure and blacks out the texture
Fixed! UE-65129 Samples rendering darker than expected or ideal
Fixed! UE-65694 Crash opening TM-Decals in -DX11 with Forward Shading enabled
Fixed! UE-65711 Instant crash when selecting viewmode “Material Texture Scales”
Fixed! UE-65697 Crash opening TM-Decals in -DX12 or - with Forward Shading enabled
Fixed! UE-65533 One off crash launching packaged Infiltrator Demo with -dx12
Fixed! UE-64820 Hang when Merging Actors QAGame asset SM_Proxy_Box with Merge Materials Enabled
Fixed! UE-64695 Lighting from Directional Lights Dims While Moving Around in Editor with Forward Shading Enabled
Fixed! UE-65102 Exposure Metering Mode “Auto Exposure Basic” Disables Histogram Min/Max Control
Fixed! UE-65717 Crash in PostProcessAmbientOcclusion.cpp when opening TM-Decals with -DX12//OpenGL4 and ForwardShading
Fixed! UE-65730 Decals with Forward Shading Render Black
Fixed! UE-65470 Crash opening package with Forward Shading
Fixed! UE-65585 [CrashReport] UE4Editor_Engine!FMaterial::GetShaderMapToUse() [materialshared.cpp:562]
Fixed! UE-62873 UMG Animation spin box not updating when key is at the end of the playback range
Fixed! UE-65672 Tracks with empty space sometimes do not compile correctly in Sequencer UI
Fixed! UE-63336 Fix ranges in 4280319
Fixed! UE-64742 Crash opening ActionRPG with -game
Fixed! UE-65097 Unreal Studio: Multi User Viewer Template Menu: Next Arrow Bug
Fixed! UE-65351 QAGame Samples Build - Various errors in Rob Gray map preventing job from completing successfully
Fixed! UE-65355 Recursion crash creating a child of a blueprint component and giving it the same name
Fixed! UE-65257 Scrollbars in Output Log can become incorrectly sized when scaling the window horizontally or clearing the output log
Fixed! UE-65543 Copy & Paste are missing from Static Mesh Asset Picker List
Fixed! UE-65521 Editor crashes when attempting to reimport multiple Data Table assets that do not have an associated data source file
Fixed! UE-64838 Reset Layout option does not reset layout to default in Subeditor Windows
Fixed! UE-64981 Morph Targets have black sections when animating
Fixed! UE-64501 [CrashReport] UE4Editor_UnrealEd!UReimportFbxStaticMeshFactory::Reimport() [editorfactories.cpp:5426]
Fixed! UE-65302 SyncPathsFromSourceControl crash
Fixed! UE-65570 Generate and Invalidate Project ID do not function fully
Fixed! UE-65554 Disabled High Resolution Screenshot option still functions as enabled
Fixed! UE-65548 FBX Import Options has missing space on an option
Fixed! UE-65427 Media Texture source file browse button does not open the file explorer
Fixed! UE-61968 [CrashReport] UE4Editor_MediaAssets!UMediaPlayer::GetPlaylistRef() [mediaplayer.h:890]
Fixed! UE-65400 Niagara InitRHI crash when opening QAGame TM-ShaderModels
Fixed! UE-65279 Custom HLSL nodes crash the editor when dragging any output onto empty input pin
Fixed! UE-65510 Crash when cooking Niagara for DirectX 10
Fixed! UE-65693 Ensure occurs when attempting to create a blank emitter from the New Emitter Wizard
Fixed! UE-65568 TM-ShaderModels game crashes in DX11 if or OpenGL is included in package
Fixed! UE-65552 Niagara GPU particles do not render in Dx12
Fixed! UE-63380 The options drop-down arrow for inputs in the stack shouldn’t be a tab-stop.
Fixed! UE-63496 Niagara GPU Particles do not render in
Fixed! UE-64927 Niagara GPU emitters are not displayed in non-cooked game
Fixed! UE-65110 Renaming a Niagara emitter from the Selected Emitters dialog clears module parameters
Fixed! UE-65796 Niagara Systems in world fail to reinitialize when DataInterface parameters are changed
Fixed! UE-59768 Crash: spawning more than 6k particles in this nearly empty map results in a crash
Fixed! UE-65768 Skeletal Mesh DI does not post an error in stack when a Skel Mesh is not assigned
Fixed! UE-65794 Log Spam from some DataInterfaces that fail to initialize
Fixed! UE-65199 Widget blueprint details continuously shift when moving objects in the widget designer
Fixed! UE-65490 Crash when undoing a copy in VRMode
Fixed! UE-65393 Empty Controller Files Generated by the Editor Are Not Being Recognized by SteamVR Input As Binding Options
Fixed! UE-65495 Magic Leap: tint on media player
Fixed! UE-65476 Editor Crashes when running with - and a Connected Vive Headset
Fixed! UE-65107 Orientations are inverted on GoogleAR
Fixed! UE-65099 Spawned actor does not remain in fixed world location when device moves
Fixed! UE-65479 Decals are only rendering in the left eye
Fixed! UE-65720 Haptic Feedback Effect must decompress before submission
Fixed! UE-61753 Excess deferred depth copy added in for 4.20
Fixed! UE-64034 Scene Depth Buffer corruption with VR on AMD GPUs
Fixed! UE-65726 Lumin updates for 4.21
Fixed! UE-65550 Crash when physical size is 0 for a candidate image to be detected in a scene
Fixed! UE-65780 Image Write - Improve cryptic error message
REMEMBER: Please report any new bugs you find by following the How To Report a Bug Guide