Editor Crash when trying to build lighting ( UE 4.7 preview 8)



Access violation - code c0000005 (first/second chance not available)

Ensure condition failed: false [File:d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\math\UnrealMatrix.h] [Line: 268]
FMatrix::Inverse(), trying to invert a NIL matrix, this results in NaNs! Use Inverse() ins

UE4Editor_UnrealEd + 10402899 bytes
UE4Editor_UnrealEd + 10403584 bytes
UE4Editor_UnrealEd + 9948679 bytes
UE4Editor_UnrealEd + 10235724 bytes
UE4Editor_UnrealEd + 10003537 bytes
UE4Editor_UnrealEd + 10778393 bytes
UE4Editor_UnrealEd + 10777364 bytes
UE4Editor_UnrealEd + 6722801 bytes
UE4Editor!FEngineLoop::Tick() + 4084 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launchengineloop.cpp:2240]
UE4Editor!GuardedMain() + 479 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launch.cpp:131]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]

Hi charlie177,

Can you post your crash logs here? They can be found at \Unreal Projects\PROJECTNAME\saved\logs. Thank you!

Here it is

link text

Does this occur in a blank project with no additional content or is it limited to one project?

Hi, we are having this same issue on our project.
Debugging, I’ve seen that what is failing are the instanced meshes from the foliage tool.
Here is where visual breaks:

And this is the call stack:

It seems that lightmass creates a kind of copy of the actors thar are going to be builded, and it crashes while doing this.


It seems that some object has an invalid transform and in here:

It tries to inverse an invalid matrix and this is where it fails.

Please, we need help URGENTLY with this, thanks!

How much foliage is in your project? Additionally, are you using speedtree or another program to create your meshes or are they already in editor? Are you using dynamic or static lighting as well?

We are using static lighting, this problem only occurs when executing the Editor from visual , (I think this isn’t the same problem that haves charlie177)
We don’t have so much foliage in our project… maybe 300 or 400 instances by map.
We aren’t using speedtree, they are all meshes imported directly from 3dmax.

Hey Yannick,

I’ve not been able to reproduce this at all on my end. Is this only happening in the particular project or have you tried to see if it’s replicating in new project?

I have not been able to reproduce any crashes regarding Lightmass that have been listed.

In the next week or so I will be adding general Lightmass Troubleshooting and tips for common errors with lightmass to this guide: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

Keep a check on that for helpful information about lightmass troubles.

Thank you!