Are emissive lights in CPU and GPU Lightmass broken? → It works with substrate and gpulightmass in 5.7.
Edit: you need to enable ‘use emissive for static lighting‘ on the static mesh with the emissive material
You can’t use WPO in materials when using new procedural foliage. (I hope this is a temporal limitation).
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Operating System: openSUSE Tumbleweed 20251111
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-1-default (64-bit)
Graphics Platform: X11
Processors: 16 × Intel® Xeon® W-2145 CPU @ 3.70GHz
Memory: 128 GiB of RAM (125.5 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 4070
Manufacturer: Dell Inc.
Product Name: Precision 5820 Tower
works well , there was a couple of minor gui glitchyness with the 5.7 git version pre release (31/10/2025) but this now seems to be resolved , most of that appeared to be a down to the kde gnome application window managment issue from what i can tell , but could also of been a conflict with ue5.7 and google chrome fighting for gpu (not had time to verify what actualy resolved it other than there both gnome apps ) maybe updating to a newer kde plasma version may help
This type of crash usually indicates a shader error, clear out all your caches in your app data directory, and any build, intermediate directories for the project you are trying to load.
I had the same crash even after loading and working on my project, after clearing it all out, and letting the engine rebuild all the shader files, it worked fine.
It only takes one shader that is corrupted to cause this to happen it can be in the content provided by Epic or something related to your project.
UE4 Projects Failing to Launch since the Launcher update before UE5.7 release (19.0.2 Update Status)
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Can’t start the editor, I’m getting crash on startup every single time. I tried verifying files and reinstalling this version to no avail. 5.6.1 works just fine. Crashlog:
LoginId:b272149447f152fce9b3ebac5b10cc7d
EpicAccountId:deccaeee99924d5e80cee0fd56c42dad
Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Developer\DerivedDataCache\Private\DerivedDataBackends.cpp] [Line: 208]
Unable to use default cache graph ‘InstalledDerivedDataBackendGraph’ because there are no writable nodes available.Add -DDC-ForceMemoryCache to the command line to bypass this if you need access to the editor settings to fix the cache configuration.
UnrealEditor_DerivedDataCache
UnrealEditor_DerivedDataCache
UnrealEditor_DerivedDataCache
UnrealEditor_DerivedDataCache
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll
have you been able to fix that cook error?
I removed wpo wind from shaders graphs. Also took out also extra detail (material functions), removed shared wrap from texture samples, added set material attritubes with only needed inputs. Quite unknown what was causing the error, but managed to cook without errors.
Cooked build is still running odd. Frame time jumps very high ~25ms, while GPU/GameThread andother hit is only 7-11ms. Also even basic landscape grass dosent appear during play. Wondering if the frame time hit is from those voxel trees. Didnt have that kind of hit in UE5.6 and only updated trees when got in UE5.7. :S Unless niagara data channels are working strange. There is new batch node to write to niagara data channel.
Currently cooking dev build to do testing with unreal insight.
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Got Garbage Collection crash during cooked play. Source Effect Chain causing crash when cue ends. That effect chain have simple delay in it:
Object SoundCue /Game/SaOKStuff/X/Sounds/Modern_Weapons_SFX_Part_I/Construction_Kit/M39_EMR_Marksman_Rifle/M39_EMR_OneShot_4_Cue.M39_EMR_OneShot_4_Cue (0x000001e90bd83620) from cluster SoundCue /Game/SaOKStuff/X/Sounds/Modern_Weapons_SFX_Part_I/Construction_Kit/M39_EMR_Marksman_Rifle/M39_EMR_OneShot_4_Cue.M39_EMR_OneShot_4_Cue (0x000001e90bd83620 / 0x000001e8cbe889d0) is referencing 0x000001e88a324300 SoundEffectSourcePresetChain /Game/SaOKStuff/VoiceActors/SoundDelayChain.SoundDelayChain which is not part of root set or cluster.
You have to provide more information such as the related/suspected log lines - saying it failed to launch can be of many unknown reasons. Or any machine spec, o/s.
(post deleted by author)
I also had constant crashing issues inside the Editor in 5.7, I fixed it by adding this to the DefaultEngine.ini inside my project files.
[/Script/RHI.RHISettings]
bEnableGPUBreadcrumbs=False
bEnablePixEvents=False
and launching your project with the -vulkan flag through your terminal.
Now its running (mostly) fine, although i don’t work with raytracing in that project, so your experience may vary. UI issues are still present for me (with x11 as well), although it’s only submenus and toolbars popping up on a different monitor, as for now.
I fixed some UI issues on my end by modifying my windowrules (I use Hyprland), so I can’t give any tips on how to solve that Nobara.
That is unfortunately not possible with my distro without significant breakage of packages.
Thanks for the tips, unfortunately in my case it doesn’t seem to help. I’ve noticed that most of the crashing seems to be specific to Nanite foliage, since it’s experimental I guess it may be expected to some extent.
Hello, just wanted to share that the current fix is only temporary.
The problem keeps coming back. As soon as you launch an older engine version, like UE 5.6, and then try to go back to 5.7, the crash hits again. This means you have to delete those folders repeatedly every single time you switch between engine versions.
Is there a more permanent solution?
I cant use Rider with 5.7 on Linux besides the other problems already mentioned
20:38:25.690: Setting up Unreal Engine project files…
20:38:25.694: /opt/unreal-engine/Engine/Build/BatchFiles/Linux/SetupDotnet.sh: line 50: syntax error near unexpected token fi 20:38:25.694: /opt/unreal-engine/Engine/Build/BatchFiles/Linux/SetupDotnet.sh: line 50: fi
20:38:25.694: /opt/unreal-engine/Engine/Build/BatchFiles/Linux/GenerateProjectFiles.sh: line 35: dotnet: command not found
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It’s in the video and its all over UDN its a launcher issue as I outline with the unrealselector.exe pointing to the wrong path for UE4. I’ve provided multiple workarounds…. just look into the like 5 forum post covering this issue or look up the UDN issue.
Fix: Restore Lumen support for D3D Shader Model 5 (DX11/DX12 SM5)
Unreal Engine 5.7 broke Lumen on D3D SM5 due to StochasticLighting shader
requiring 8 UAVs (hardware limit: 4 UAVs). This commit restores full Lumen
functionality with a fallback path that combines UE 5.6’s simpler approach
with 5.7’s compatibility requirements.
Key Changes:
- StochasticLighting.cpp: D3D SM5 detection, simplified 2-UAV depth/normal copy
- Created LumenTileBitmask with all tiles marked (0xFF) for 5.7 compatibility
- LumenScreenProbeGather.cpp: Fixed GI temporal validation (check data not pointer)
- LumenReflectionDenoiserTemporal.usf: Conditional depth read for D3D SM5
- New shader: StochasticLightingDenoising.usf (5.6-style history storage)
Result:
Full Lumen GI + Reflections working on DX11 and DX12 SM5
DX11 SM5 with Lumen SWRT is fastest performing Lumen path
Quality identical to SM6+, no tile culling optimization
Production ready, tested across multiple scenarios
Files Modified:
- StochasticLighting.cpp (fallback path + LumenTileBitmask creation)
- LumenScreenProbeGather.cpp (temporal validation fix)
- LumenReflections.cpp (D3D SM5 comment)
- LumenReflectionDenoiserTemporal.usf (depth consistency)
- LumenScreenProbeGatherTemporal.usf (PackedPixelData validation)
- StochasticLightingDenoising.usf (new 5.6-style shader)
- DeferredShadingRenderer.h (function declaration)
- LUMEN_D3D_SM5_FIX_SUMMARY.md (comprehensive documentation)
Update: PRs Open for both Main and Dev for those on that branch who want to put it through the paces.
Main - https://github.com/EpicGames/UnrealEngine/pull/14056
Dev-5.7 - https://github.com/EpicGames/UnrealEngine/pull/14055
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Thank you so much for your work on the source to regain SM5 functionality! I found the github commit from epic for the irradiance field gather method that was added to the main branch; which did not make it into 5.7 release. It looks like it may be viable enough in its current state. I may merge it with the additions made to SM5 branch, for a pretty good perf boost on top. Here is the link to the github commit if anyone is interested in adding it in:
https://github.com/EpicGames/UnrealEngine/commit/fead0b4f3cfc6262371837867d16e8aea3345481
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I have hundreds of plugins and content from the Fab store. Nothing is compatible and nothing works with 5.7 paid or otherwise. Nothing will install from the Epic Launcher. 90% of my plugins are compatible up to 5.4
Not even Epic plugins that are in the tutorials for how to use content in 5.7 You still tell us to use plugins from within Fab that are not compatible for 5.7 but it’s in the Epic tutorials! Either update your plugins or fix your tutorials or allow us to install content and plugins for previous versions again!
Most of them are just model packs and simple content. Why are we no longer allowed to import models from Fab into our projects if they are no longer marked compatible for the specific engine we are working with? Having to redownload another version of the engine and manually copy files over is such a waste of time. Not being allowed to install or use my paid for plugins and content is a total scam!
Where has the support gone for these forums? 5.7 has broken everything and nobody seems to have any answers.
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