Corrupted level after building light!

I have a serious problem with my project. Every time I build my light (or in some cases, for other reasons), my level becomes laggy (sometimes it uses 14 GB of Ram) and if I close the engine and try to open the project again, the level corrupts and don’t open again. It’s funny that sometimes it’s corrupt autosaves and I can’t restore my level by them and I have to backup my level manually to restore it! what can I do? It’s a serious problem and I don’t know, what can I do! ;'(
This is the error massage that I get when I try to open my corrupted level:

Assertion failed: TheModel->Nodes.IsValidIndex( NodeIdx ) [File:D:__03__Engines\UnrealEngine4.4.0\Engine\Source\Runtime\Engine\Private\ModelRender.cpp] [Line: 99]
Invalid Node Index, Idx:24, Num:24
Stack:
FWindowsPlatformStackWalk::StackWalkAndDump() 0xeaf25bb6 + 0 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\core\private\windows\windowsplatformstackwalk.cpp:177] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-Core.dll]
FDebug::AssertFailed() 0xeadc4535 + 0 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\core\private\misc\outputdevice.cpp:203] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-Core.dll]
Address = 0xe6263133 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-Engine.dll]
Address = 0xe6292d12 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-Engine.dll]
UObject::ConditionalPostLoad() 0xeaa1cb5a + 0 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\coreuobject\private\uobject\obj.cpp:592] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-CoreUObject.dll]
Address = 0xe6b2267f (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-Engine.dll]
UObject::ConditionalPostLoad() 0xeaa1cb5a + 0 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\coreuobject\private\uobject\obj.cpp:592] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-CoreUObject.dll]
EndLoad() 0xeaa87816 + 0 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1112] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-CoreUObject.dll]
LoadPackage() 0xeaa96e28 + 62 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:826] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-CoreUObject.dll]
Address = 0xe907eb74 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe9070ebd (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe905c841 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe937c8d0 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe90e0ce4 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe90e09a8 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe93ac8c0 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
Address = 0xe937b850 (filename not found) [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
GuardedMain() 0x3f11cbbd + 0 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\launch\private\launch.cpp:125] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor.exe]
GuardedMainWrapper() 0x3f11ccea + 5 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\launch\private\windows\launchwindows.cpp:125] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor.exe]
WinMain() 0x3f128ad9 + 17 bytes [File=d:__03__engines\unrealengine4.4.0\engine\source\runtime\launch\private\windows\launchwindows.cpp:201] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor.exe]
__tmainCRTStartup() 0x3f129989 + 21 bytes [File=f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618] [in D:\UE 4\UnrealEngine4.4.0\Engine\Binaries\Win64\UE4Editor.exe]
Address = 0x771e59ed (filename not found) [in C:\Windows\system32\kernel32.dll]
Address = 0x7731c541 (filename not found) [in C:\Windows\SYSTEM32\ntdll.dll]
Address = 0x7731c541 (filename not found) [in C:\Windows\SYSTEM32\ntdll.dll]

Hey Sachamora -

After some research it appears this crash is actually being caused by a material on a specific model being indexed incorrectly. Before the light build, did you add any specific models or perhaps a material which is referencing something in Blueprints that has to do with the light build?

Take a look and let me know -

Thank You

Eric Ketchum

thanks for the reply but can you elaborate more on material being indexed incorrectly? what does it mean?

In the static mesh editor if you open a mesh, you will notice that there is an Element 0 listed at the top, and occasionally if your mesh takes multiple materials will be an Element 0, 1, 2, etc… These are indices for the mesh. My thoughts were that there may be a material that is being applied in a blueprint but is referencing an incorrect index for the mesh it is being applied to, but again this is just a hypothesis.

Thank You

Eric Ketchum

Thanks. I got it now, but that’s not my case. I tried various things and finally when I reduce lightmap resolutions of my meshes, the level didn’t corrupt and I could play it after building light. I wonder why it happens. Can’t I increase lightmap resolutions more than a specific value?

Thank You.

There is the texture size limit in the engine which is 4096x4096 (technically 8192x8192 but performance is so bad I always recommended the next size down.) However, the light build is totally dependent on the machine running the build so there may be a memory cap on your machine that will not allow the specified size. In that case I would look at increasing the virtual memory of the machine or if that doesn’t work then updating the Physical Memory would be next.

Thank You

Eric Ketchum