Crash on export of Large Nanite Mesh

I have hundreds of large nanite objects, that I need to export to FBX for use in a blender process. I have found I need to turn Nanite off, and enabled full precision UV’s for the FBX to have an accurate export, and textures to line up correctly. I have been able to export about 125 models fine without issue, until I hit a larger model than the others, that is now giving me the crash:

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION writing address 0x0000020669944048

I have tried to troubleshoot this issue by updating my graphic drivers, I used a backup version of my mesh thinking my file may have corrupted. I have also tried saving my files to a different drive to check if the folder I was saving them was broken as well. If anyone has any ideas I would greatly appreciate it.

I am running in ue5.1

EDIT:
I have multiple pieces that are crashing the editor. They all are trending to be above 25 mil polygons, compared to the others that aren’t failing are ranging from 4 mil to 18 mil polygons.

My computer specs are:

AMD Ryzen Threadripper 3960X 24-Core Processor
256 GB Ram
RTX 3090

looks like a hardware limit issue, maybe not enough memory. what are you computer specs? try closing all apps and maybe put unreal on lowest graphic settings.

My computer specs are:

AMD Ryzen Threadripper 3960X 24-Core Processor
256 GB Ram
RTX 3090

I’ll try putting unreal on the lowest graphic setting and try there

I gave that try and it still crashed. I am also using world Partition, so I did it with none of my world assets loaded.

well that looks more than enough actually. have no idea then what could be.

maybe try ue5.0 if possible just to export these assets, maybe it works

Yeah I’m working on a pretty beefy machine, I tested in 5.0 with the same crash as before. I also gave a .obj export a go as well, and it crashed mid export leaving me with a corrupted file that wont import into blender.

I’ve started experimenting with .USD format, and I was able to export it very quickly and easily. I just will have to put in a bit more extra effort into making it work with my process in blender if FBX is going to fail on larger sets.

Let me know if you have any ideas, but otherwise I think I have exhausted all of my willpower to try, and will give USD a go lol.

I am having issues with .usd imports into blender causing issues. So I am trying again to see if there is a solution out there on fixing the FBX export crashes. So if anyone stumbles down here I’m still on the lookout.

I was able to export the bulk of my meshes as .fbx, and then exported the Large Nanite meshes remaining as .gltf which was stable. Though when I took it into blender I had to merge the vertices to repair some lost connection for some of the polygons. So gltf worked and I was able to export my meshes out of blender as .fbx after my work was done and they imported to unreal fine.

I am not going mark this as a “Solution” because I believe there is still the question as to why the fbx exporter wasn’t working. But to anyone in the future who may run into the same issue this was my work around.