Editor version 4.7.6 on windows 7.
I have a 10 by 7 grid of 2k by 2k landscapes loaded by the tiled landscape “auto” loader. World Composition is ON and Origin rebasing is OFF. I worked around the error by moving them closer to 0,0 than they were placed by the autoloader but thought this issue should be recorded so you can fix the problem and others can possibly find a quick solution,
full dump follows:
Error === Lightmass crashed: ===
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.7\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 679]
Array index out of bounds: 17707360 from an array of size 17707360
KERNELBASE.dll!UnknownFunction (0x000007fefd55aaad) + 0 bytes [UnknownFile:0]
UnrealLightmass-Core.dll!UnknownFunction (0x000007fecacc4544) + 0 bytes [UnknownFile:0]
UnrealLightmass-Core.dll!UnknownFunction (0x000007fecaba28c8) + 0 bytes [UnknownFile:0]
UnrealLightmass-Core.dll!UnknownFunction (0x000007fecab81075) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!Lightmass::TkDOPTree::SplitTriangleList() (0x000000013fe2a9f9) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!Lightmass::TkDOPTree::Build() (0x000000013fdde0c9) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!Lightmass::FStaticLightingAggregateMesh::PrepareForRaytracing() (0x000000013fe19aba) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!Lightmass::FStaticLightingSystem::FStaticLightingSystem() (0x000000013fdc0333) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!Lightmass::BuildStaticLighting() (0x000000013fdde951) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!Lightmass::LightmassMain() (0x000000013fe14f72) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!main() (0x000000013fe31950) + 0 bytes [UnknownFile:0]
UnrealLightmass.exe!__tmainCRTStartup() (0x000000013fe86467) + 0 bytes [UnknownFile:0]
kernel32.dll!UnknownFunction (0x00000000776359cd) + 0 bytes [UnknownFile:0]
ntdll.dll!UnknownFunction (0x000000007776b891) + 0 bytes [UnknownFile:0]
ntdll.dll!UnknownFunction (0x000000007776b891) + 0 bytes [UnknownFile:0]