FBX Import crash

Static mesh crashes on FBX import in UnrealEngine; appears to allocate lots of memory and hangs-up computer:

S_A_Seat1_UnrealCrash.fbx: 1 object, 288K Polygons, 146K Vertices (5.3MB).

This is part of much larger mesh (70 objects) which otherwise loads fine.

Tested three UnrealEngine versions, with same effect: 4.7.6; 4.8.1 and 4.8.2;


  • HP Pavilion 17-e019dx, Windows 8.1 64-bit, 8GB RAM and very large page file, 700GB HD, Intel(R) Core™ i3-4000M CPU @ 2.40GHz (4 CPUs), ~2.4GHz, Intel(R) HD Graphics 4600 [*** note below];

[*** Updated to version to fix “Build Lighting” crash]

Link (5.3MB file):

Thanks for your help!

Hi -

Thank you for your report. We will begin investigation into this issue as soon as possible. If you can please post your Machine ID that is generated from the Unreal Crash Reporter when the Editor Crashes, also please make sure your submit the report so we can easily find the pertinent information.

In the meantime, please be sure to review our suggestions for how to report a bug, and feel free to edit your post if you have additional information to provide:

Thank you -

Eric Ketchum

What program did you use to make the fbx?

Thanks, Eric for helping us with S_A_Seat1_UnrealCrash.fbx. I have not submitted UnrealCrashReporter because system hangs up and freezes during FBX import in all Unreal versions we tested, with simple import into “Blank” project.

Thanks for your work and fast response :slight_smile:

This S_A_Seat1_UnrealCrash.fbx was saved from MS Visual Studio after finding single object/node in cusomer’s file that crashes Unreal and hangs up system. Same effect when exported from Blender: Import into Unreal crashes.

Original file (70 objects) came from customer - I can find out how they made it if you need this info. I opened this FBX with other applications (such as Microsoft Visual Studio or AutoDesk’s FBX Review, QuickTime with FBX plugin, or import into Unity engine, Blender - all work fine.

Hi -

The Chair is significantly high poly which shouldn’t be a problem for the editor and on my PC it takes about 5 to 10 mins to fully import. Since you are attempting to import it on a PC with only 8GB RAM and an Intel Integrated Graphics Card it will take an exceptionally longer time to finish importation. (The PC I am testing on is a 32GB RAM, NVidia GTX770.)

Since the engine never crashes, it is still trying to process the import and if you do not get a Windows crash that means you computer is still attempting to process the asset and it will eventually import or your PC will run out of memory and Windows will force the Engine to close (Windows Error without the Crash Reporter popping up.)

Some things you can do to help the import Process along is to pre-Triangulate your model in the modeling software. If you leave it quads only, the engine has to process the triangulation which will take some time. You can also not generate UV Lightmaps in the Editor but have them pre-made from your modeling software. Finally you can uncheck generate collision.

Ultimately I would try to use the mesh you have as a hi-poly normal generator for a much lower poly mesh.

Thank You -

Eric Ketchum

Thanks for fast response, Eric. Rest of the image (34MB Objects=77 Polygons=1321599 Vertices=667966) loads fine, import takes only 5 minutes or so… I experimented with import settings such as without collision and UV lightmap. With submitted image, Editor and Windows freeze and require a reboot. I will try on NVIDIA system in a few days…

Hey -

Just keep in mind unless Windows crashes or you get an error file on your PC it may take hours to fully finish (I’ve seen this happen on extremely Hi-poly landscapes that people try to bring into the engine on lower end PCs.)

Eric Ketchum

I asked because I too have found Unreal’s fbx import to be very fragile. We ran into a lot of crashing issues while importing fbx’s from Modo. We finally got a process that seems to work that involves triangulated the mesh and then performing a mesh cleanup in Modo and then exporting to fbx (in that order). This may not help you, but yes Unreal’s fbx importing needs work for sure.

Thanks you were right - this large object allocates cumulative RAM above 8GB and burns through the page file for about an hour. This is the largest object in 70+ node file and takes over an hour to import without UV lightmap and collision… NVIDIA+32GB RAM will help!!! Thanks for very prompt and hands-on response, u rule!

Thanks for your feedback: Pre-triangulated mesh is what Eric suggested as well here… We are early in the project and running into some glitches in import as well, but what looked like a crash was +1hr import burning through the pagefile above 8GB ram. Again, Thanks!!!