Unreal Engine 5.1 Preview

Ready to take new Unreal Engine features for a spin? Unreal Engine 5.1 Preview 1 is now available on the Epic Games launcher or GitHub for Windows and Mac, or via Linux - Unreal Engine for Linux. The Preview builds are made available so you can test-drive new features and help us catch issues before the final release. As fixes are implemented, we will release updated previews throughout the development cycle.

Please be aware that preview releases are not fully quality tested, are still under heavy active development, and that they should be considered as unstable until the final release.

Developers should not convert their projects for active development on preview releases. Please test on copies of your project instead.

Links to known and fixed issues for this release are provided below. If you discover any additional issues with this preview release, please report them using the guidelines in the link: How to Report a Bug.

Known & Fixed Issues

5.1 Preview Summary

Unreal Engine 5.1 improves upon the features delivered with the release of UE5, creating more streamlined and easy-to-use workflows for real-time 3D content creation.

Developers will see improved performance with Lumen, Nanite, and Virtual Shadow Maps (VSM), now supporting games running at 60 fps on next generation consoles and PCs. Build expansive worlds using new functionality and improved workflows for World Partition, including support for Large World Coordinates. And enjoy significant improvements to cinematic pipelines, such as performance and usability improvements for ICVFX.

Explore the in-depth list of features and updates coming in Unreal Engine 5.1—please note, not all updates may be listed, and complete release notes will be available with the final 5.1 release.

Unreal Engine 5.1 Public Roadmap

Fixed in Preview 2

Issue Summary
UE-166649 Media: Incorrect display of loop point when the section is offset
UE-162704 Touch and Mouse Input Incorrectly Routed in Pixel Streaming Output Provider When Windows Scaling is not 100%
UE-114649 UV Editor subwindows cannot be restored - can result in crash
UE-163742 World Partition causes client to disconnect from dedicated server
UE-166089 ARKit tracking and livelink source sometimes not registering with Pixel Streaming VCam
UE-166080 Large frame rate hit when recording a CineCameraActor
UE-161172 [MetaSounds][Surround Formats] - 5.0 Output Format does not map surround channels correctly on 5.1+ systems
UE-166203 Graphical artifacts on the surface of the Single Water Material with Strata and DX12 enabled
UE-164951 [Solidworks] Directional light should not be created.
UE-164394 Closing the editor with Quick Launch running on device freezes, prevents running Quick Launch again without restarting computer
UE-163961 Remote Control Logic - Bind Behavior Values Not Updating Live
UE-164565 Range Behavior Value Interpolation Not Working
UE-166321 Child Actor in level duplicating itself each time a blueprint is compiled
UE-159668 [Quartz] Play Quantized Crashes When Played On An Audio Component Spawned With ‘Persist Across Level Transition’
UE-166234 [Quartz] - Start Other Clock fails to start new clock
UE-166237 [Quartz] - Clock does not persist through loading a new level when Ignore Level Change is True
UE-165877 Remove Common section from Parameters panel
UE-163441 Some Thumbnails are missing in the Content Browser/Asset Creation Dialog
UE-160075 Users can’t disable key snapping on curve user parameters
UE-166415 Crash when right clicking UVEditor tab - Assertion failed: UVEditorToolkit.cpp [Line: 323]
UE-166490 World partitioned dynamic navmesh not working in DYNAMIC_MODIFIER_ONLY mode
UE-145924 DatasmithSketchupExporter 2022 - crash on macOS M1
UE-156027 ImgMedia: Converting a media plate to spawnable will cause a crash
UE-166171 Merge, VoxWrap, VoxMorph invalidating input mesh position
UE-164294 MaterialX - Missing function output connections with some materials
UE-166763 Rifle Sound Effect Loops infinitely after firing
UE-166767 Capture Progress Sound does not play
UE-166172 Lyra - Shadows Flickering in Main Menu & In-Game
UE-166156 Multiple ‘Simulate Physics’ Warnings Fire in Output Log when running package
UE-166637 LWC - Water plugin has no water meshes to draw at 2 trillion units
UE-166313 Crash while moving around in LWCRendering
UE-165966 Interchange - GLTF - Error when trying to re-import textures attached to mesh
UE-166839 Crash when reloading a Retargeter Asset after any changes
UE-166594 Changes to Retarget Phases in Global Settings do not save after project close
UE-166825 Popping EXR tiles even with upscaling
UE-166423 Minimum cache setting causes slower video/EXR performance in PIE vs in-editor
UE-166726 DMX - DMXDisplayClusterLightCardComponent shows MaxLatitude property at the wrong location in UI
UE-166518 DMX - Editor crash while adding function to a fixture (pure virtual function being called)
UE-166727 DMX - Exporting an MVR scene ignores transforms from the level
UE-166573 DMX - Auto Assign Right Click in Library Patch doesn’t update UI properly
UE-166311 Pixel Mapping - Custom Attributes are not reflected in modulator options
UE-166480 DMX - Potential access violation in FDMXEntityReferenceCustomization which could cause a crash when modulators in pixelmapping were selected
UE-166194 Editor Crashes in Landscape Mode after attempted to create a new Landscape
UE-166818 Crash adding renderer to an Emitter
UE-165687 Lyra Crashes when Applying Changes in Options
UE-156921 Crash on loading level with Landscape by 2 PIE instances
UE-164348 Crash after Reloading LayerBlend Material and switching back to Linked LayerBlend Material Instance in QAGame
UE-166257 PixelStreaming memory leak crash when loading level with saved active VCam
UE-166235 Crash occurs when adding a new pin to the Layered Blend Per Bone node and compiling
UE-166135 Crash upon using mouse after using gamepad
UE-166224 Title crash when saving a current file with edit layers set as locked
UE-166494 Crash when trying to render queue on World Partitioned map with Streaming disabled
UE-166946 Crash when switching viewmode to Shader Complexity while PIE
UE-166896 Crash opening level in specific project.
UE-165954 Editor crashes after closing and opening Light Card Editor Viewport for In-Camera VFX
UE-165916 Packaged FPS game is stuck in a black screen when launched on
UE-164966 Landscape updating forever on open world map due to texture loop
UE-163550 Crash when switching between material asset tabs after an asset is reloaded
UE-166545 Unhandled Exception Crash when compiling an Animation Blueprint
UE-160453 [MetaSounds][Wave Player] - Looping sound waves is not sample accurate
UE-166569 [MetaSound] [Analysis] Analyzers do not work on connections immediately off inputs
UE-161170 [MetaSounds][Wave Player] - 5.0 Wave Player node exists; however, editor doesn’t support 5.0 files
UE-165949 Crash occurs after trying to delete Kernel node or Skinned Mesh node connected to setup within Deformer Graph
UE-161188 Update TechSoft Exchange with 2022 Sp2 does not work on Linux
UE-126644 [Audio Modulation] Parameter Mismatch error gets shown when using user-created Modulation Parameter of the correct type
UE-165754 Build batch file using installed .NET instead of the bundled UE version
UE-156178 ISR: Volumetric Cloud Rendering artifacts with HighQualityAerialPerspectiveOnCloud
UE-164821 Deformer Graph Shader Text Editor needs an icon
UE-133993 Solidworks udatasmith exporter does not support configurations
UE-166133 Crash when using the Gameplay Media Encoder
UE-166765 Fuzz test bink audio encoder
UE-151022 Navmesh not created around the cube after simulating on TM-TestNavMesh level with Dynamic Runtime Generation
UE-166050 [AI] StateTree - All bindings to StateTree Enums are broken
UE-166926 Crash occurs when saving a Motion Database asset after attaching a Database Config to it
UE-166497 Blendspace behavior is broken when used with Motion Matching
UE-166701 Control Rig : Can’t resolve copy/pasted function
UE-165896 Control Rig Display Actor is not visible in packaged projects
UE-166704 Control Rig : Bad Math using aggregate node
UE-166320 ControlRig&Sequencer: Select a control rig track in sequencer causes the character to appear blurry (zero motion vectors)
UE-165891 Deleting and Recreating Constraint manager Should hook up existing constraints
UE-166856 ControlRigComponent crashes when recompiling a ControlRigBP with a variable
UE-165974 Control Rig: Aim Constraint Node has the wrong category
UE-166378 Control Rig : Python Script : ‘RigControlType’ has no attribute ‘VECTOR2_D’
UE-166299 Unable to create variables in a Deformer Graph asset
UE-166540 Multiple LogPBIKSolver: Warning: PBIK: warnings thrown when using Change Retarget Asset button
UE-163695 Animations will stutter and restart when anim is set to Transition Leader in a Sync Group and is blended into
UE-166228 Skeleton Compatibility not saved
UE-166651 Crash when loading a layered bone per blend node that has empty blend mask entries
UE-166725 Crash when compiling Anim BP with Pose Driver
UE-165998 Creating an attach track in Sequencer while using World Partition invalidates CL
UE-166240 Perlin Noise parameter changes not updating immediately
UE-166243 Collapse/Expansion State isn’t restored properly for some object bindings
UE-166361 Tracks in folders fail to be added to groups
UE-166032 Constraints: Can’t pose a child if it’s both point and orient constrained.
UE-166324 Undoing a change in Curve Editor with a Constraint resets the current view or causes crash
UE-165402 Multiple errors thrown when modifying Shocker_BP while simulating
UE-165936 [Source Effect] - Set BypassSource Effect Preset Chain Entry at a negative array index crashes editor
UE-165938 [Source Effect] - Remove Source Effect from Preset Chain at a negative Entry Index crashes editor
UE-165929 [Audio Modulation][Audio Buses] - Editor crashes if an Audio Bus used by an Envelope Follower Generator is set as a Default Audio Bus
UE-163142 [MetaSounds] High Bit Depth settings in the Bitcrusher filter results in odd output on repeated Plays
UE-165926 [MetaSounds] - AnalyzerAddress shows as a type on the MetaSounds graph
UE-161404 Spectral Analysis Delegates Do Not Behave As Expected If 3 Or More Are Attached To The Same Submix
UE-165728 Lyra poisons user preferences for using Escape to exit PIE
UE-157260 Memory leak in Datasmith Retessellate & Dataprep Tessellate
UE-165887 Duplicating and reimporting a texture cube with a new file fails.
UE-165518 LWC_LevelEditTool value boxes show an A instead of numbers
UE-166781 Rename of SetEditableTextStyle to avoid change in public API
UE-166794 Editable text boxes without font are not displayed properly
UE-166796 There is no default font set for (single line) editable text box.
UE-166112 CoreLimit no longer working
UE-166958 Async Loading might not deserialize objects prior to PostLoad
UE-166291 Can not comment out UE_INLINE_GENERATED_CPP_BY_NAME line
UE-166656 Gameplay Cue Editor icon needs to be updated
UE-163922 open asset in editor crash (Objects have the same fully qualified name but different paths)
UE-165955 Crash when displaying collision for landscape with Simple Mip Collision Level > 0
UE-166754 UGS unable to build Licensee workspaces due to plugins
UE-166425 Iris plugin incorrectly labeled Beta instead of Experimental
UE-165593 Entire VisualStudio solution in VS2019 can’t be built in Source Build Workspace (SymsLibDump)
UE-165600 Entire VisualStudio solution in VS2022 can’t be built in Source Build Workspace (SymsLibDump)
UE-166335 XcodeBuild.sh emitted errors but did not return a nonzero exit code to indicate failure
UE-166082 Crashed on TVOS(Apple A8) when loading reflection capture
UE-166853 Update Android to NDK 25b
UE-166076 Oculus Mobile Crash on Launch
UE-166386 Clicking the right/left analog sticks in OculusVR does not close the menu
UE-166351 VR Template menu cursor drifts after opening
UE-166091 OpenXR: Ensure failed - XR_ERROR_PATH_UNSUPPORTED on entering Virtual Scouting
UE-165128 Ensure condition failed: SingleShaderBindings.GetParameterMapInfo().SRVs.Num() == 0
UE-166561 D3D12 + Forward + MSAA: Failed ensure in FRHIRenderPassInfo::Validate on startup, corrupted rendering
UE-155378 Wobbling effect on meshes
UE-165989 mGPU performance regression in nDisplay
UE-166418 Performance issue with FillRayTracingInstanceUploadBuffer due to reading write-combined memory
UE-166728 Crash when enabling Shader Complexity Viewmode
UE-165993 Hardware Raytracing is rendering like Software Raytracing on Linux
UE-166816 Shading mode expression is incorrectly connected when converted to Strata
UE-158544 Remove/replace uses of master/slave found in NiagaraEditor with base folder Source
UE-166750 DI categories collapse/expand wrongly when working with members if there are multiple of the same present
UE-162605 Changing parameters of an emitter inherited from another is lagging
UE-160594 Niagara editor killing systems in the editor and pie worlds on loop.
UE-165740 IsAllowedClass not compatible with RendererCreationInfos refactor
UE-166062 Stash crashes frequently when working with niagara effects
UE-166367 Crash when running Heterogeneous Volumes with Hardware Ray Tracing enabled
UE-166844 Fix compositing for 2D fluid sims
UE-166352 Crash when applying a scratch module
UE-166492 WindForce Enums are not refreshed and cause output spam.
UE-165759 Content Examples are using outdated modules and old versions- Needs update pass
UE-165523 GPU timing in Insights tracing is incorrect
UE-166907 Fix rare issue in Vulkan Defrag
UE-166803 Missing hair lighting when a groom is lit by both a shadow casting light and a non-shadow casting light.
UE-166866 Strata Materials only use Tangent Space Normals
UE-166658 Strata Debug Visualization Doesn’t Scale with Screen Percentage
UE-166249 Strata legacy conversion is using raw integer instead of ShadingModel node
UE-164772 Cloth solver becomes unstable with large changes in timestep
UE-166068 Chaos : Player cannot interact physically with geometry collection
UE-161613 Trace Box query is failing or reporting the wrong point
UE-166812 Zero length sweeps fail and print log errors
UE-166333 Distortion ST Maps from Shogun cannot be imported correctly
UE-165575 LogPlayLevel: Error: UAT: DVP_ERROR: Initialization failed thrown when exiting a quick launched project
UE-166002 Aja / Blackmagic output keeps old frame or show green when shutdown abrutly
UE-166405 Remote Control Intermittent Crash in RCWidget Registry
UE-165732 Web Remote Control - CCR and Lightcard Panel Feature Conform Pass
UE-166229 Web Remote App - WebRemoteUI layout/properties exposed within a Multi-User session are not updated when rejoining the session after restarting UE
UE-162457 Remote Control Preset, Protocols/Logic Button do not work when opening another Preset.
UE-162436 Preset panel content does not scale or provide scroll bars to view content properly
UE-166486 Remote Control Preset Undo/Redo is not working
UE-166095 MRQ with nDisplay Mesh policy doesn’t work
UE-166096 MRQ with nDisplay ProceduralMesh policy doesn’t work
UE-166739 MRQ + nDisplay: crash editor after run Render multiple times
UE-165855 Editor crash with Vioso nDisplay config on Dx12
UE-165713 Editor crash when deleting UV light card from app.
UE-166587 Missing Threadobj.Reset in FDisplayClusterTcpListener
UE-165878 Lightcard references being lost when restoring level snapshots
UE-164717 nDisplay - Freeze viewport might offset nDisplay output
UE-165615 Skylight: Skylight don’t work properly in the outer viewport in ndisplay.
UE-166849 Fix mismatch of default imgmedia caching threads and all the tests made for performance
UE-166838 UnrealMultiUserSlateServer is not pre-built for release builds.
UE-166219 Multi-User Server: Missing Correct Taskbar Icon at All Resolutions
UE-166216 [Crash] Playlist crash when starting a take record with a sequence set to be held
UE-166426 Current Bookmark text does not update correctly
UE-166428 Dial value tooltip too small to be read
UE-166430 Dial Text does not wrap
UE-166598 Dial text wobbles when changing lens preset
UE-166431 Dial bounds are not scaled by number of entries
UE-166048 Releasing a right joystick with the left joystick down will release both
UE-166427 Bookmark actor always reads TEXT and not its name
UE-166590 VCAM actor does not override resolution on iPad by default
UE-166028 Lens Preset fails to limit aperture on VCamDial
UE-164506 VCam PixelStreamingOutputProvider routes clicks to windows over the viewport
UE-166433 Sequencer Timeline and Transport Controls can be bumped during recording
UE-166029 Near Clip override is off by default in VCamActor and Modifier does not set it
UE-162703 VP Roles Toolbar doesn’t have an Icon
UE-166340 Access to the VR Editor mode should be removed
UE-166437 AndroidFileServer hardcoded in template projects

Is there a way to try the preview release ?

It’s available in the launcher…


I can only find 5.0.3

1 Like

It’s in there. Close the launcher and restart… at the Library tab click the + sign next to Engine versions… it will add what looks like 4.27 under version… next to that click the drop down and select 5.1 preview.


You need to do an windows update if you do have an update to install for windows 10 or 11, then you restart your pc. And after when it’s finished restarting, then you go back to epic games lanucher to see 5.1 preview update

1 Like

Found it it is like a little hidden, thanks


No problem man :+1:t4:

Nice, it comes with the very first update of the Plastic SCM plugin, v1.6.2 with support for the new Changelists UI :slight_smile:
Since the last version that was integrated was v1.4.6 in UE4.24 nearly 3 years ago!



Any plans to add support for metadata using Datasmith?

1 Like

Does anyone know how to enable multi GPU for path tracer?

Really neat to see experimental hardware raytracing support in the Vulkan RHI (So using the editor or native game builds on Linux should soon be on-par with Windows), alongside the new PSO gathering system (Much needed since shader compilation stutter won’t be as big of an issue anymore), and the Strata Materials system. I really appreciate the work being done to improve the editor and engine in many aspects. I do have some questions though regarding the status of certain things in the engine.

I do wonder if the Strata Materials system will allow for custom BSDFs (like toon shading) without requiring a 200GB fork of the engine, post-process materials (Which have plenty of limitations), or faking things using unlit materials (Which comes at the cost of dynamic shadows). Here’s hoping I can switch from forward rendering to deferred soon.

I’m also wondering if there’s plans on revamping how HDR works on UE5. Based on my time using it on my OLED display (For getting HDR support working), the image (even with sample content) looks drastically different from the SDR variant (looks far darker and has more of a yellow tone), and with emissive materials in the material editor (When I have HDR set to be used in the editor), the preview for the color in the material editor rapidly strobes between different colors. So far, I’ve found that retrofitting HDR using Special K usually has better results in games than using the native support, which is a bit of a shame.

That said, I do have some things that would be great to see addressed in the future regarding input devices (like controller support, where the XInput support leaves a ton of room for improvements).

I do wonder if there’s going to be some work done to how the Steam Controller plugin works. It’s functionality has been a bit redundant since SteamInput profiles allowed for simultaneous Keyboard/Mouse + Controller input, and it would be neat to see a rewrite that takes full advantage of the SteamInput API (action based rebinding with interoperability with Unreal’s existing input system, a way of grabbing input glyphs based on what an input action or input axis is set to, and other features that API supports). With the Steam Deck and non-XInput controller types becoming more common to use, it would be nice to see a rewrite of the plugin. From my time attempting to implement SteamInput support in my own project, the problem is that the existing methods to implement it can be a bit hacky.

Likewise, the Windows RawInput plugin still has problems with incorrect bindings on DualShock/DualSense controllers when you have it plugged in through Bluetooth compared to over USB (I have noticed this when testing my own stuff to try and implement support for PlayStation controllers). Although I do wonder if there’s plans to natively support alternate controllers out of the box with a system similar to what Unity’s NewInput system allows.


Any reason why this major issue has been pushed to 5.2?


5.1 still running as an Intel app on an M1 Mac… What happened to the Apple Silicon Support?!


@Carlrizien I have no need to use a Mac, but, preview means BETA…it’s not the final product yet. Only treat this version as a test version of the engine. [just in case] do not convert current ‘real work’ over to it as BETA versions tend to break things.


Will there be tessellation or at least a good alternative for it in 5.1?

1 Like

I was wondering is there a way to use the hot live code with blueprints to communicate better to develop UMG or other assets. I am coming from a website developer aspect, where I can develop the website and see what is being developed.

As said many time, tesselation will never come back in unreal engine.

Virtual Height Field is the way for landscape.
And Nanite mesh don’t need tesselation.

What you mean @Sk3l3tor by hot live code ? You mean hot reload ?


Is this any different from the GitHub 5.1 released earlier last month?

1 Like

How will there be snow deformation?