Fbx file crashes when importing from 3ds max


I’m creating a archviz scene and trying to import bunch of models but this particular model keeps failing. I tried quad and triangulated version of this model but no success, had the Smoothing Groups checked when exporting. I need to import another similar curved window frame but this curved one also failed. It’s a bit too big to upload.

I checked on the model thoroughly, made sure face normal direction, etc. but couldn’t figure out any possibility so decided to remodel the same one and the new one is fine to FBX import. The attached model is the old one with issues.

This is the crash report:

Unknown exception - code 00000001 (first/second chance not available)

Assertion failed: ChartB.Join[ Side ^ 1 ] == i [File:\BuildFarm\buildmachine_++depot+UE4-Releases+4.5\Engine\Source\Developer\MeshUtilities\Private\LayoutUV.cpp] [Line: 374]

KERNELBASE + 37901 bytes
UE4Editor_Core + 3174852 bytes
UE4Editor_Core + 1677512 bytes
UE4Editor_Core + 1566866 bytes
UE4Editor_MeshUtilities + 214770 bytes
UE4Editor_MeshUtilities + 143459 bytes
UE4Editor_Engine + 8364051 bytes
UE4Editor_Engine + 8365276 bytes
UE4Editor_Engine + 8345177 bytes
UE4Editor_UnrealEd + 9321344 bytes
UE4Editor_UnrealEd + 8895211 bytes
UE4Editor_UnrealEd + 9024407 bytes
UE4Editor_AssetTools + 936464 bytes
UE4Editor_AssetTools + 931311 bytes
UE4Editor_ContentBrowser + 1512721 bytes
UE4Editor_ContentBrowser + 1233391 bytes
UE4Editor_Slate + 2103098 bytes
UE4Editor_Slate + 2285477 bytes
UE4Editor_Slate + 822092 bytes
UE4Editor_Slate + 756518 bytes
UE4Editor_Core + 2506393 bytes
UE4Editor_Core + 2450091 bytes
UE4Editor_Core + 2510873 bytes
UE4Editor_Core + 2438466 bytes
user32 + 105425 bytes
user32 + 104666 bytes
UE4Editor_Core + 3157718 bytes
UE4Editor!FEngineLoop::Tick() + 3106 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\launchengineloop.cpp:2111]
UE4Editor!GuardedMain() + 479 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\launch.cpp:133]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\windows\launchwindows.cpp:125]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\windows\launchwindows.cpp:201]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]

Branch: a ‘Binary’ build from the Unreal Launcher

Version: 4.5.1-2336687+++depot+UE4-Releases+4.5

Description: FBX crash when importing

System: windows7, i5-3570, 16GB RAM, Quadro FX5600

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Hi Sailors,

Thank you for reporting this. This is a known issue that affects some FBX imports (UE - 3032). I’ve updated some notes and added this AH post to that bug report as well.

As a workaround you can import the mesh into UE4 by unchecking the “Generate Lightmap UVs” when the Import Options window is open. This is where the hitch is happening that is causing the crash. If you need/want lightmap UVs you’ll need to create them in your modeling software for this particular mesh or any meshes that are causing the crash to occur.

Once a fix has been submitted I’ll verify and update this post with any and all relevant information.

Thank you!


This bug has recently been fixed and will be in 4.7. You can test this out with the 4.7 preview builds that are currently available via the launcher or once the final build of 4.7 is released.

The fixed CL is 2400339.

Thank you!