Lightmass fails to compile in VS, results in Swarm failed to kick off.

So everything seemed to work fine with the new release, untill I tried building lights for any scene or new/old project. The error “Swarm failed to kick off” is displayed. I have completely removed the new UE4 release and rebuilt it from source from scratch 2 times with the same error. Ive never had any issues compiling UE4 source before.

Build config: Development Editor, win64

final build log shows:

47> -------- End Detailed Actions Stats -----------------------------------------------------------
47> Total build time: 2162,09 seconds
========== Build: 20 succeeded, 0 failed, 1 up-to-date, 27 skipped ==========

Trying to rebuild only Lightmass in VS results in these compile errors:

Severity	Code	Description	Project	File	Line	Suppression State
Error	MSB3073	The command "..\..\Build\BatchFiles\Build.bat UnrealLightmass Win64 Development -waitmutex" exited with code -1.	UnrealLightmass	C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets	37	
Error	C3861	'_mm_cvtpu8_ps': identifier not foundh:\unrealengine-release\engine\source\programs\unreallightmass\private\lightmasscore\math\LMMathSSE.h(586): error C3861: '_mm_cvtpu8_ps': identifier not found	UnrealLightmass	h:\unrealengine-release\engine\source\programs\unreallightmass\private\lightmasscore\math\LMMathSSE.h	586	
Error	C3861	'_mm_cvtpu8_ps': identifier not found	UnrealLightmass	h:\unrealengine-release\engine\source\programs\unreallightmass\private\lightmasscore\math\LMMathSSE.h	586	
Error		Failed to produce item: H:\UnrealEngine-release\Engine\Binaries\Win64\UnrealLightmass.exe	UnrealLightmass	H:\UnrealEngine-release\Engine\Intermediate\ProjectFiles\ERROR	1	

I have even tried reinstalling and reparing VS installation but it seems to work fine…
Any help is very appreicated, I am completely stuck. Here is the start of the compile log:

1>------ Rebuild All started: Project: EnvVarsToXML, Configuration: Development Any CPU ------
2>------ Rebuild All started: Project: DotNETUtilities, Configuration: Development Any CPU ------
3>------ Rebuild All started: Project: DeploymentInterface, Configuration: Development Any CPU ------
4>------ Skipped Rebuild All: Project: MobileDeviceInterface, Configuration: Development Any CPU ------
4>Project not selected to build for this solution configuration 
5>------ Rebuild All started: Project: AutomationToolLauncher, Configuration: Development Any CPU ------
2>  DotNETUtilities -> H:\UnrealEngine-release\Engine\Binaries\DotNET\DotNETUtilities.dll
5>  AutomationToolLauncher -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationToolLauncher.exe
1>  EnvVarsToXML -> H:\UnrealEngine-release\Engine\Binaries\DotNET\EnvVarsToXML.exe
6>------ Skipped Rebuild All: Project: GitDependencies, Configuration: Development Any CPU ------
6>Project not selected to build for this solution configuration 
7>------ Rebuild All started: Project: HTML5LaunchHelper, Configuration: Development Any CPU ------
3>  DeploymentInterface -> H:\UnrealEngine-release\Engine\Binaries\DotNET\IOS\DeploymentInterface.dll
7>  HTML5LaunchHelper -> H:\UnrealEngine-release\Engine\Binaries\DotNET\HTML5LaunchHelper.exe
8>------ Rebuild All started: Project: UnrealBuildTool, Configuration: Development Any CPU ------
9>------ Skipped Rebuild All: Project: iPhonePackager, Configuration: Development Any CPU ------
9>Project not selected to build for this solution configuration 
10>------ Skipped Rebuild All: Project: DeploymentServer, Configuration: Development Any CPU ------
10>Project not selected to build for this solution configuration 
8>  UnrealBuildTool -> H:\UnrealEngine-release\Engine\Binaries\DotNET\UnrealBuildTool.exe
11>------ Rebuild All started: Project: AutomationUtils.Automation, Configuration: Development Any CPU ------
12>------ Rebuild All started: Project: ShaderCompileWorker, Configuration: Development_Program x64 ------
13>------ Skipped Rebuild All: Project: SymbolDebugger, Configuration: Development_Program x64 ------
13>Project not selected to build for this solution configuration 
14>------ Skipped Rebuild All: Project: TestPAL, Configuration: Development_Program x64 ------
14>Project not selected to build for this solution configuration 
15>------ Skipped Rebuild All: Project: UnrealCEFSubProcess, Configuration: Development_Program x64 ------
15>Project not selected to build for this solution configuration 
16>------ Skipped Rebuild All: Project: UnrealCodeAnalyzer, Configuration: Development_Program Win32 ------
16>Project not selected to build for this solution configuration 
17>------ Skipped Rebuild All: Project: UnrealFileServer, Configuration: Development_Program x64 ------
17>Project not selected to build for this solution configuration 
18>------ Skipped Rebuild All: Project: UnrealFrontend, Configuration: Development_Program x64 ------
18>Project not selected to build for this solution configuration 
19>------ Skipped Rebuild All: Project: UnrealHeaderTool, Configuration: Development_Program x64 ------
19>Project not selected to build for this solution configuration 
20>------ Skipped Rebuild All: Project: UnrealLightmass, Configuration: Development_Program x64 ------
20>Project not selected to build for this solution configuration 
21>------ Skipped Rebuild All: Project: CrashReportClient, Configuration: Development_Program x64 ------
21>Project not selected to build for this solution configuration 
22>------ Skipped Rebuild All: Project: UnrealSync, Configuration: Development_Program x64 ------
22>Project not selected to build for this solution configuration 
23>------ Skipped Rebuild All: Project: UnrealVersionSelector, Configuration: Development_Program x64 ------
23>Project not selected to build for this solution configuration 
24>------ Skipped Rebuild All: Project: BootstrapPackagedGame, Configuration: Development_Program x64 ------
24>Project not selected to build for this solution configuration 
25>------ Skipped Rebuild All: Project: BlankProgram, Configuration: Development_Program x64 ------
25>Project not selected to build for this solution configuration 
26>------ Skipped Rebuild All: Project: BuildPatchTool, Configuration: Development_Program x64 ------
26>Project not selected to build for this solution configuration 
27>------ Skipped Rebuild All: Project: MinidumpDiagnostics, Configuration: Development_Program x64 ------
27>Project not selected to build for this solution configuration 
28>------ Skipped Rebuild All: Project: CrossCompilerTool, Configuration: Development_Program x64 ------
28>Project not selected to build for this solution configuration 
29>------ Rebuild All started: Project: UnrealLaunchDaemon, Configuration: HTML5_Development_Program x64 ------
30>------ Skipped Rebuild All: Project: DsymExporter, Configuration: Mac_Development_Program Win32 ------
30>Project not selected to build for this solution configuration 
31>------ Skipped Rebuild All: Project: ShaderCacheTool, Configuration: Development_Program x64 ------
31>Project not selected to build for this solution configuration 
32>------ Skipped Rebuild All: Project: UE4EditorServices, Configuration: Development_Program x64 ------
32>Project not selected to build for this solution configuration 
33>------ Skipped Rebuild All: Project: UnrealAtoS, Configuration: Mac_Development_Program Win32 ------
33>Project not selected to build for this solution configuration 
34>------ Skipped Rebuild All: Project: UnrealPak, Configuration: Development_Program x64 ------
34>Project not selected to build for this solution configuration 
35>------ Skipped Rebuild All: Project: ParallelExecutor, Configuration: Development_Program x64 ------
35>Project not selected to build for this solution configuration 
36>------ Skipped Rebuild All: Project: SlateViewer, Configuration: Development_Program x64 ------
36>Project not selected to build for this solution configuration 
29>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets(41,5): warning MSB8005: The property 'NMakeReBuildCommandLine' doesn't exist.  Skipping...
12>  Cleaning ShaderCompileWorker Binaries...
11>  AutomationUtils.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationUtils.Automation.dll
37>------ Rebuild All started: Project: GUBP.Automation, Configuration: Development Any CPU ------
38>------ Rebuild All started: Project: IOS.Automation, Configuration: Development Any CPU ------
39>------ Rebuild All started: Project: AllDesktop.Automation, Configuration: Development Any CPU ------
39>  AllDesktop.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\AllDesktop\AllDesktop.Automation.dll
40>------ Rebuild All started: Project: Linux.Automation, Configuration: Development Any CPU ------
38>  IOS.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\IOS\IOS.Automation.dll
40>  Linux.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\Linux\Linux.Automation.dll
41>------ Rebuild All started: Project: Mac.Automation, Configuration: Development Any CPU ------
42>------ Rebuild All started: Project: TVOS.Automation, Configuration: Development Any CPU ------
37>  GUBP.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\GUBP.Automation.dll
43>------ Rebuild All started: Project: AutomationScripts.Automation, Configuration: Development Any CPU ------
42>  TVOS.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\TVOS\TVOS.Automation.dll
41>  Mac.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\Mac\Mac.Automation.dll
44>------ Rebuild All started: Project: Win.Automation, Configuration: Development Any CPU ------
44>  Win.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\Win.Automation.dll
43>  AutomationScripts.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\AutomationScripts.Automation.dll
45>------ Rebuild All started: Project: Android.Automation, Configuration: Development Any CPU ------
46>------ Rebuild All started: Project: HTML5.Automation, Configuration: Development Any CPU ------
45>  Android.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\Android\Android.Automation.dll
46>  HTML5.Automation -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationScripts\HTML5\HTML5.Automation.dll
47>------ Rebuild All started: Project: AutomationTool, Configuration: Development Any CPU ------
47>  AutomationTool -> H:\UnrealEngine-release\Engine\Binaries\DotNET\AutomationTool.exe
12>  Creating makefile for ShaderCompileWorker (no existing makefile)
12>  Performing full C++ include scan (no include cache file)
12>  Performing 84 actions (4 in parallel)
12>  [3/84] Resource PCLaunch.rc
12>  [4/84] Resource ModuleVersionResource.rc.inl
12>  PCH.CorePrivatePCH.h.cpp
12>  PCH.Core.h.cpp
12>  [5/84] Resource ModuleVersionResource.rc.inl
12>  [6/84] Resource PCLaunch.rc
12>  [7/84] Resource PCLaunch.rc
12>  [8/84] Resource ModuleVersionResource.rc.inl
12>  [9/84] Resource PCLaunch.rc
12>  [10/84] Resource ModuleVersionResource.rc.inl
12>  [11/84] Resource ModuleVersionResource.rc.inl
12>  [12/84] Resource PCLaunch.rc
12>  [13/84] Resource PCLaunch.rc
12>  [14/84] Resource ModuleVersionResource.rc.inl
12>  [15/84] Resource PCLaunch.rc
12>  [16/84] Resource ModuleVersionResource.rc.inl
12>  [17/84] Resource ModuleVersionResource.rc.inl
12>  [19/84] Resource PCLaunch.rc
12>  Module.ImageWrapper.cpp
12>  [20/84] Resource ModuleVersionResource.rc.inl
12>  [21/84] Resource PCLaunch.rc
12>  Module.RHI.cpp
12>  Module.RenderCore.cpp

I can confirm that Lightmass fails to build and seems to be the cause. I spent the entire day nuking/formating all my harddrives and reinstalling the entire system from scratch, and the exact same problem occures with a fresh install of Windows 7 (all updates) and Visual Studio 2015 community (all updates)…

Need assistance as soon as possible. Will try to work with binary build meanwhile, but I really really need the source build to work properly.

The same compile errors are given for Lightmass in visual studio once again:

Severity	Code	Description	Project	File	Line	Suppression State
Error	MSB3073	The command "..\..\Build\BatchFiles\Build.bat UnrealLightmass Win64 Development -waitmutex" exited with code -1.	UnrealLightmass	C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets	37	
Error	C3861	'_mm_cvtpu8_ps': identifier not found	UnrealLightmass	h:\unrealengine-release\engine\source\programs\unreallightmass\private\lightmasscore\math\LMMathSSE.h	586	
Error	C3861	'_mm_cvtpu8_ps': identifier not found	UnrealLightmass	h:\unrealengine-release\engine\source\programs\unreallightmass\private\lightmasscore\math\LMMathSSE.h	586	
Error	C3861	'_mm_cvtpu8_ps': identifier not found	UnrealLightmass	h:\unrealengine-release\engine\source\programs\unreallightmass\private\lightmasscore\math\LMMathSSE.h	586	
Error		Failed to produce item: H:\UnrealEngine-release\Engine\Binaries\Win64\UnrealLightmass.exe	UnrealLightmass	H:\UnrealEngine-release\Engine\Intermediate\ProjectFiles\ERROR	1

This is because we updated to visual studio update 2. you can temp do a build if you generate a -2013 project files.

this is a duplicate of Failed to build UnrealLightMass.exe on Promoted Branch - Programming & Scripting - Epic Developer Community Forums

Very interesting, I tried redownloading, installing and compiling the previous 4.10.4 build, and it compiles and runs fine with Visual Studio (update 2).

Will try generating 2013 project files. Thanks for helping out!

EDIT: Lightmass seems to have compiled with the “build solution” for 4.10, but trying to rebuild it alone after the initial project build would fail.

Hello,

I have been able to reproduce this compiler error, and have entered a bug report (UE-29050). Thank you for your report. I will provide updates on this issue as they become available.

Have a great day

I worked around this temporarily by copying the Lightmass.exe from the prebuilt version (4.11.1) into my source win64 bin dir.

Just an update, this issue was fixed in the 4.11.1 hotfix! Cheers