# \#building-lighting **URL:** https://forums.unrealengine.com/tag/building-lighting/620.md [Latest](https://forums.unrealengine.com/latest.md) · [Categories](https://forums.unrealengine.com/categories.md) · [Tags](https://forums.unrealengine.com/tags.md) --- ## [UE5.4 MacOS Building Lighting consistantly failing - connection timeout?](https://forums.unrealengine.com/t/ue5-4-macos-building-lighting-consistantly-failing-connection-timeout/2317664)
**Author:** [@bsack23](https://forums.unrealengine.com/u/bsack23)\ **Replies:** 9\ **Last updated:** [July 19, 2026, 7:51pm UTC](https://forums.unrealengine.com/t/ue5-4-macos-building-lighting-consistantly-failing-connection-timeout/2317664 "2026-07-19T19:51:50Z")
I’m using UE5.4 on a computer that belongs to a university - I am not able to change firewall settings to allow incoming connections. I am also unable to successfully build lighting - at all. Even the simplest possible … --- ## [Unreal (5.4.4 and 5.6 Preview) Lightmass on Mac stopping at 0%](https://forums.unrealengine.com/t/unreal-5-4-4-and-5-6-preview-lightmass-on-mac-stopping-at-0/2530543)
**Author:** [@GameAnim](https://forums.unrealengine.com/u/GameAnim)\ **Replies:** 15\ **Last updated:** [April 22, 2026, 6:41pm UTC](https://forums.unrealengine.com/t/unreal-5-4-4-and-5-6-preview-lightmass-on-mac-stopping-at-0/2530543 "2026-04-22T18:41:55Z")
I am unable to get Unreal to build lighting on an Apple MacBook Pro M4, with it stopping at 0% before failing, and offering no errors beyond: LogStaticLightingSystem: Warning: Failed to build lighting!!! Lighting build … --- ## [Rect Lights - barns not working on static lights - ies profile not working](https://forums.unrealengine.com/t/rect-lights-barns-not-working-on-static-lights-ies-profile-not-working/509469)
**Author:** [@geverk](https://forums.unrealengine.com/u/geverk)\ **Replies:** 4\ **Last updated:** [April 2, 2026, 7:27pm UTC](https://forums.unrealengine.com/t/rect-lights-barns-not-working-on-static-lights-ies-profile-not-working/509469 "2026-04-02T19:27:11Z")
Hi, I have noticed that Rect lights do not work properly when you assign a IES profile, it becomes a punctual light. So I tried to emulate the effect using the barn angle and length but those options only work on stati… --- ## [T.array resize error ](https://forums.unrealengine.com/t/t-array-resize-error/2678172)
**Author:** [@chris457k](https://forums.unrealengine.com/u/chris457k)\ **Replies:** 1\ **Last updated:** [November 24, 2025, 6:16pm UTC](https://forums.unrealengine.com/t/t-array-resize-error/2678172 "2025-11-24T18:16:54Z")
Project setup: Map size: nearly 5 km Environment: Imported from Fab https://www.fab.com/listings/35ca06cf-a124-44aa-b2ac-5b233223f3a2 Engine: UE 5.5 (no major changes to the environment after import) Scalabi… --- ## [UE5 - VirtualTextureAllocator crash when building lighting with GPULightmass](https://forums.unrealengine.com/t/ue5-virtualtextureallocator-crash-when-building-lighting-with-gpulightmass/528258)
**Author:** [@Ozykz](https://forums.unrealengine.com/u/Ozykz)\ **Replies:** 7\ **Last updated:** [November 7, 2025, 12:51pm UTC](https://forums.unrealengine.com/t/ue5-virtualtextureallocator-crash-when-building-lighting-with-gpulightmass/528258 "2025-11-07T12:51:14Z")
I am getting the following error in UE5 when trying to build lighting: Ensure condition failed: Index \<= 0x8000 \[File:D:\\build++UE5\\Sync\\Engine\\Source\\Runtime\\Renderer\\Private\\VT\\VirtualTextureAllocator.cpp\] \[Line: 113\] … --- ## [Building lighting stuck at 0%](https://forums.unrealengine.com/t/building-lighting-stuck-at-0/401738)
**Author:** [@So\_Robro](https://forums.unrealengine.com/u/So_Robro)\ **Replies:** 14\ **Last updated:** [September 20, 2025, 2:08am UTC](https://forums.unrealengine.com/t/building-lighting-stuck-at-0/401738 "2025-09-20T02:08:45Z")
Hello, I just created a new project, an empty project. I placed directional light and sky light. I created a standart 2x2 landscape.I pressed build and it got stuck at: Building lighting 0%. I tried it again a couple ti… --- ## [Unreal Lightmass executable is outdated](https://forums.unrealengine.com/t/unreal-lightmass-executable-is-outdated/680381)
**Author:** [@eco\_bach2](https://forums.unrealengine.com/u/eco_bach2)\ **Replies:** 15\ **Last updated:** [August 8, 2025, 2:32pm UTC](https://forums.unrealengine.com/t/unreal-lightmass-executable-is-outdated/680381 "2025-08-08T14:32:06Z")
After doing a custom compile of latest 5.1 preview editor source and trying to build my lighting I get the following warning Warning: Failed to build lighting!!! Unreal Lightmass executable is outdated. Recompile Unreal… --- ## [SWARM AGENT Not installing - CANNOT BUILD LIGHTING!](https://forums.unrealengine.com/t/swarm-agent-not-installing-cannot-build-lighting/2588709)
**Author:** [@SickestHouse21](https://forums.unrealengine.com/u/SickestHouse21)\ **Replies:** 2\ **Last updated:** [July 3, 2025, 2:41pm UTC](https://forums.unrealengine.com/t/swarm-agent-not-installing-cannot-build-lighting/2588709 "2025-07-03T14:41:19Z")
I got a brand new Metabox Laptop with the new GTX5060 and Intel Ultra 9 Processor a few weeks ago and spent days transferring old files - But i ended up having to delete all my old Unreal Folders as i have attempted to r… --- ## [UE5.5.4 Crashes when trying to build lighting, even on preview quality](https://forums.unrealengine.com/t/ue5-5-4-crashes-when-trying-to-build-lighting-even-on-preview-quality/2532673)
**Author:** [@MrLowFps123](https://forums.unrealengine.com/u/MrLowFps123)\ **Replies:** 2\ **Last updated:** [June 7, 2025, 12:39pm UTC](https://forums.unrealengine.com/t/ue5-5-4-crashes-when-trying-to-build-lighting-even-on-preview-quality/2532673 "2025-06-07T12:39:32Z")
I am trying to build the lighting for a mid-sized level with a lot of static/stationery lighting, but it crashes- its weird becuase even if I hide everything in my map, it still crashes when building. Log: UnrealEditor… --- ## [Far Cry 6 Esperanza city environment](https://forums.unrealengine.com/t/far-cry-6-esperanza-city-environment/2289430)
**Author:** [@Saraawwad1](https://forums.unrealengine.com/u/Saraawwad1)\ **Replies:** 12\ **Last updated:** [April 13, 2025, 12:13pm UTC](https://forums.unrealengine.com/t/far-cry-6-esperanza-city-environment/2289430 "2025-04-13T12:13:32Z")
Hello, I’m excited to kick-off a Far Cry 6 inspired tropical island environment as a first environment to work on this year as part of my last year of masters in videogames art. It has a Latin American infrastructure wi… --- ## [GPU Lightmass support for RX7000/RDNA3 GPU's](https://forums.unrealengine.com/t/gpu-lightmass-support-for-rx7000-rdna3-gpus/2450307)
**Author:** [@stormergames001](https://forums.unrealengine.com/u/stormergames001)\ **Replies:** 0\ **Last updated:** [April 10, 2025, 9:33pm UTC](https://forums.unrealengine.com/t/gpu-lightmass-support-for-rx7000-rdna3-gpus/2450307 "2025-04-10T21:33:22Z")
My question is simple, what are the known issues/compatibility for GPU lightmass lightmap baking with AMD RX7000/RDNA3 GPU’s? I am using an RX 7900 XTX and I have had zero success with baking light maps through GPU light… --- ## [\[UE5.3.2\] Commandline lighting build incorrect skylight lighting](https://forums.unrealengine.com/t/ue5-3-2-commandline-lighting-build-incorrect-skylight-lighting/2082198)
**Author:** [@Joost](https://forums.unrealengine.com/u/Joost)\ **Replies:** 0\ **Last updated:** [October 23, 2024, 7:58am UTC](https://forums.unrealengine.com/t/ue5-3-2-commandline-lighting-build-incorrect-skylight-lighting/2082198 "2024-10-23T07:58:52Z")
After updating from 4.27 to 5.3.2 (Oculus fork), when building lighting with UnrealEditor-Cmd.exe skylights seem to only cast white light instead of using the specified cubemap/ scene capture. Building the same level th… --- ## [Unusual grid-like artifact appearing in render \[UE5-01\]](https://forums.unrealengine.com/t/unusual-grid-like-artifact-appearing-in-render-ue5-01/530821)
**Author:** [@wesviz](https://forums.unrealengine.com/u/wesviz)\ **Replies:** 1\ **Last updated:** [May 19, 2024, 10:30pm UTC](https://forums.unrealengine.com/t/unusual-grid-like-artifact-appearing-in-render-ue5-01/530821 "2024-05-19T22:30:30Z")
Hi everyone, Happy to be working on my first visual using UE5 official! Im on a fast-turnaround job, so might not get the answer in time and right now working and patching up in after effects as needed. I have a simple… --- ## [Lighting in shipping too dark compared to in editor](https://forums.unrealengine.com/t/lighting-in-shipping-too-dark-compared-to-in-editor/461334)
**Author:** [@RMVR](https://forums.unrealengine.com/u/RMVR)\ **Replies:** 10\ **Last updated:** [May 4, 2024, 2:55pm UTC](https://forums.unrealengine.com/t/lighting-in-shipping-too-dark-compared-to-in-editor/461334 "2024-05-04T14:55:25Z")
Does it happen when you simulate the game in the editor? Usually the issue lies in difference between exposure settings, so if you have edited the exposure settings of the ingame camera or in some post process node, that… --- ## [Unreal Engine 4.27.2 - Problem Building Lighting](https://forums.unrealengine.com/t/unreal-engine-4-27-2-problem-building-lighting/1795892)
**Author:** [@DustyShinigami](https://forums.unrealengine.com/u/DustyShinigami)\ **Replies:** 0\ **Last updated:** [April 9, 2024, 5:25pm UTC](https://forums.unrealengine.com/t/unreal-engine-4-27-2-problem-building-lighting/1795892 "2024-04-09T17:25:48Z")
Hi This is primarily for UE4 as I’m following a book on the engine. However, I seem to have an issue with rebuilding the lighting. I’ve created a lit pillar that I’ve converted to a Blueprint, but as soon as I drop one … --- ## [LightmassReplace node not working with GPU Lightmass?](https://forums.unrealengine.com/t/lightmassreplace-node-not-working-with-gpu-lightmass/550200)
**Author:** [@Pantoth](https://forums.unrealengine.com/u/Pantoth)\ **Replies:** 1\ **Last updated:** [March 8, 2024, 8:28am UTC](https://forums.unrealengine.com/t/lightmassreplace-node-not-working-with-gpu-lightmass/550200 "2024-03-08T08:28:41Z")
Hi everyone! After switching from good old CPU Lightmass to GPU Lightmass (and some tinkering with Luoshuang’s GPU Lightmass) I’m at a point where I’m happy with the result. But what I discovered recently: The really g… --- ## [Building Lighting turns objects black. Again](https://forums.unrealengine.com/t/building-lighting-turns-objects-black-again/561808)
**Author:** [@Last\_Farmer](https://forums.unrealengine.com/u/Last_Farmer)\ **Replies:** 6\ **Last updated:** [November 7, 2023, 4:02pm UTC](https://forums.unrealengine.com/t/building-lighting-turns-objects-black-again/561808 "2023-11-07T16:02:58Z")
Hi. Well, I have created just a simple room, but the damned light building turns everything black even if… Meshes are imported form Maya as .FBX -They have normals facing out. And they have UVs (channel 0) The applie… --- ## [Lighting blown out on just one mesh](https://forums.unrealengine.com/t/lighting-blown-out-on-just-one-mesh/319546)
**Author:** [@Bafftub](https://forums.unrealengine.com/u/Bafftub)\ **Replies:** 1\ **Last updated:** [October 10, 2023, 9:30pm UTC](https://forums.unrealengine.com/t/lighting-blown-out-on-just-one-mesh/319546 "2023-10-10T21:30:53Z")
So I’ve set up an interior scene. I have a directional light in the scene, but I’ve set it so that it doesn’t effect anything in the scene, I’ve Put a lightmass importance volume in the scene, I’ve adjusted the global po… --- ## [Build Lighting from command line](https://forums.unrealengine.com/t/build-lighting-from-command-line/490252)
**Author:** [@wurrego](https://forums.unrealengine.com/u/wurrego)\ **Replies:** 3\ **Last updated:** [September 21, 2023, 10:09pm UTC](https://forums.unrealengine.com/t/build-lighting-from-command-line/490252 "2023-09-21T22:09:27Z")
I am trying to build lighting for my map from the command line, on a remote Ubuntu 20.04 server that I am ssh’d into. Not having any luck… (Side Note: this server also succesfully runs my packaged game instances, which … --- ## [Build Lighting Not Working?! (BUG?)](https://forums.unrealengine.com/t/build-lighting-not-working-bug/758854)
**Author:** [@DELGOODIE](https://forums.unrealengine.com/u/DELGOODIE)\ **Replies:** 4\ **Last updated:** [September 8, 2023, 12:00pm UTC](https://forums.unrealengine.com/t/build-lighting-not-working-bug/758854 "2023-09-08T12:00:04Z")
So built static lights are not working when I play the game. Here are my details: Nanite Disabled Lumen Disabled (using None for GI) Virtualized Textures enabled Virtualized Textures for Lightmaps enabled Force No Pre-… --- ## [Issues building & light building](https://forums.unrealengine.com/t/issues-building-light-building/371967)
**Author:** [@ViviDDesign](https://forums.unrealengine.com/u/ViviDDesign)\ **Replies:** 4\ **Last updated:** [August 25, 2023, 1:56pm UTC](https://forums.unrealengine.com/t/issues-building-light-building/371967 "2023-08-25T13:56:46Z")
Hi, Im having issues with building my game or the lighting, it always used to work but since I’ve moved the project over to 4.12 when I build the project I get the standard progress bar pop up the like a second later it… --- ## [When to build lighting?](https://forums.unrealengine.com/t/when-to-build-lighting/1271750)
**Author:** [@riaaa](https://forums.unrealengine.com/u/riaaa)\ **Replies:** 1\ **Last updated:** [August 25, 2023, 7:07am UTC](https://forums.unrealengine.com/t/when-to-build-lighting/1271750 "2023-08-25T07:07:53Z")
This is a random question, but when should I build my lighting in my game? can I do it half way through making it or should I wait until it’s closer to being done? not all the set is done yet but I have the basic lightin… --- ## [The shadows under the trees is just too much dark](https://forums.unrealengine.com/t/the-shadows-under-the-trees-is-just-too-much-dark/485843)
**Author:** [@Player\_003](https://forums.unrealengine.com/u/Player_003)\ **Replies:** 8\ **Last updated:** [August 18, 2023, 5:07am UTC](https://forums.unrealengine.com/t/the-shadows-under-the-trees-is-just-too-much-dark/485843 "2023-08-18T05:07:11Z")
Whenever i build lighting the shadows under the trees just become too much dark https://ibb.co/wgxwH1Y --- ## [My meshes get black on Building Light on UE 5.2](https://forums.unrealengine.com/t/my-meshes-get-black-on-building-light-on-ue-5-2/1200123)
**Author:** [@Mantovictor](https://forums.unrealengine.com/u/Mantovictor)\ **Replies:** 3\ **Last updated:** [June 16, 2023, 1:35pm UTC](https://forums.unrealengine.com/t/my-meshes-get-black-on-building-light-on-ue-5-2/1200123 "2023-06-16T13:35:10Z")
Hey all. I’m having issues on baking light on UE 5.2 I have set everything from Lumen to None, also tried Standalone Ray Traced, both gives me same results. My meshes all get black, I set the light map to correct one, … --- ## [All static lights stop glowing after buildinglight](https://forums.unrealengine.com/t/all-static-lights-stop-glowing-after-buildinglight/1200522)
**Author:** [@V\_vix](https://forums.unrealengine.com/u/V_vix)\ **Replies:** 0\ **Last updated:** [June 15, 2023, 8:37pm UTC](https://forums.unrealengine.com/t/all-static-lights-stop-glowing-after-buildinglight/1200522 "2023-06-15T20:37:21Z")
I’m trying to build lights in my level to see how shiny surfaces will look with them, but every time I try to build them, all of them turn dark and stop glowing. I get the green checkmark “Lighting build completed” pop u… --- ## [Lighting build fails after stuck on 0% for a few minutes \[UE 5.1\]](https://forums.unrealengine.com/t/lighting-build-fails-after-stuck-on-0-for-a-few-minutes-ue-5-1/789306)
**Author:** [@Slydex44](https://forums.unrealengine.com/u/Slydex44)\ **Replies:** 3\ **Last updated:** [March 13, 2023, 6:23pm UTC](https://forums.unrealengine.com/t/lighting-build-fails-after-stuck-on-0-for-a-few-minutes-ue-5-1/789306 "2023-03-13T18:23:28Z")
Hi, I’m using UE 5.1 on Mac OS and it just doesn’t build lighting. I can’t see an error in log of what can cause that. Is there any suggestions? Thanks in advance! LightingResults: New page: Lighting Build - Mar 13, 20… --- ## [Baking light is not working in one level only in the proyect, probably because a blueprint.](https://forums.unrealengine.com/t/baking-light-is-not-working-in-one-level-only-in-the-proyect-probably-because-a-blueprint/776558)
**Author:** [@Alex54315](https://forums.unrealengine.com/u/Alex54315)\ **Replies:** 0\ **Last updated:** [February 22, 2023, 7:39pm UTC](https://forums.unrealengine.com/t/baking-light-is-not-working-in-one-level-only-in-the-proyect-probably-because-a-blueprint/776558 "2023-02-22T19:39:52Z")
So, I have this problem in one of the levels of my proyect, that is whenever I leave the level or close the engine and then open the level again the message of ‘LIGHTNING NEEDS TO BE REBUILT’ is always there. I’ve been … --- ## [Engine crashes after build when encoding textures](https://forums.unrealengine.com/t/engine-crashes-after-build-when-encoding-textures/377801)
**Author:** [@avarch](https://forums.unrealengine.com/u/avarch)\ **Replies:** 12\ **Last updated:** [February 7, 2023, 4:15pm UTC](https://forums.unrealengine.com/t/engine-crashes-after-build-when-encoding-textures/377801 "2023-02-07T16:15:21Z")
Hello, all of a sudden, I can’t finish the light building process anymore, since everytime it reaches the part where it says “encoding textures” it goes up till 40% and then i get the win error message that the program … --- ## [Weird lighting issue](https://forums.unrealengine.com/t/weird-lighting-issue/754929)
**Author:** [@Misstarretje](https://forums.unrealengine.com/u/Misstarretje)\ **Replies:** 12\ **Last updated:** [January 31, 2023, 1:43am UTC](https://forums.unrealengine.com/t/weird-lighting-issue/754929 "2023-01-31T01:43:35Z")
After light building some of my models have strange shading, as if the UVs are inverted. I’m still a noob in Unreal so I have no idea what the issue could be. --- ## [Why does static lightning is disappear when I'm trying to build it?](https://forums.unrealengine.com/t/why-does-static-lightning-is-disappear-when-im-trying-to-build-it/747977)
**Author:** [@Texn0krat](https://forums.unrealengine.com/u/Texn0krat)\ **Replies:** 2\ **Last updated:** [January 12, 2023, 5:56pm UTC](https://forums.unrealengine.com/t/why-does-static-lightning-is-disappear-when-im-trying-to-build-it/747977 "2023-01-12T17:56:22Z")
Hello. I have 3 light sources in my scene (stationary sky light, stationary directional light, static point light). When I’m trying to build lightning with that scene I’m getting this: Seems like my point light is… [Next page](https://forums.unrealengine.com/tag/building-lighting/620.md?match_all_tags=true&page=1&tags%5B%5D=building-lighting)