Datasmith crashes UE right after generating materials

Hi guys, I am using datasmith 5.5 to import solidworks project into UE5.5. Small test projects are handled OK, only with some small issues where some faces and objects are skipped during the import. But the real project that I actually have to focus on not only require a long wait time for the machine to process tons of objects, but right after everything is processed, and you can see the materials are generated and put in the content folder, that’s when UE just crashes.

I tried 3 ways to import: with Datasmith CAD enabled, directly import my solidworks CAD assembly file; save the CAD as udatasmith file and then import it; and direct link.

During the import process, the log shows some files couldn’t be found, and they are simply skipped. I am OK with that, as long as it gets into UE.

I really like to work with Datasmith, but this happened many times, I don’t know if I can avoid it or I have to give it up because of it.

Thank you so much for any suggestions.

Do you have the log of the crash you could share with us?
It will be in your project folder /saved/logs

Can you confirm it crashes with .udatasmith file imports too, at the step where materials are generated?
How big is you solidworks assembly?

Thank you for your kind help. Here you go.

Cesium-backup-2025.06.02-11.16.21.log.zip (156.5 KB)

It crashes after some materials popped up in the folder. My solidworks files are 20Gb. Is that too much? I wish I could ask the engineer to optimize it for me.

Do you know how to merge multiple parts into one part? I looked it up online, it’s super complicated in solidworks. If it’s absolutely necessary, I will merge them in 3dsmax.

I can see in the log what you are mentionning. It seems UE fails on some Interchange code. That should not be the case.

How do you launch the import of the sldasm in UE?
Can you confirm you are still using the Datasmith > File Import route?

I see you use rought tessellation to keep number of tris low.
And you are using Stitching Sew that is good.

You cannot easily merge parts on import at the moment.

Thank you again for your great help, sir!

Yes, I can confirm that I was using that way to import, when I directly import sldasm file, lots of elements are missing. Crash can happen. I try to import a udatasmith file, but solid works doesn’t save it successful most of the time.

Like I mentioned maybe here or another post that you replied earlier, I tried 3 ways: directly import assembly file into UE, save as udatasmith file from solidworks, and direct link.

So far I only got some success with the first way and third way when dealing with smaller assembly. The second way takes a long time and sometimes it freezes solidworks. And I couldn’t successfully save a udatasmith file after a long wait.

I don’t know anything about the details you mentioned. I didn’t do any advanced operations. I just imported the assembly, that’s all.

Maybe I can be more helpful? Let me know.

If you want to remote in to my computer, that works for me as well.

You’re the best!

I just tried to import a smaller sldasm file into UE, immediately crashed UE. Here is the log.
Cesium.zip (32.7 KB)

Thank you , the log still mention interchange, that should not be the case.
For that test too you imported through the Datasmith Import > File Import option?

Can you send a screenshot of the import dialog you get when you import the soliworks file?
It should be Something like that

I am testing UE 5.6 now. The interface is a little different. I just right click in the folder, and choose “import to current folder”,

Is this different from doing it here?

I will test more tonight.

Yes it is different,

  1. The import into folder will do an asset import so not spawning actors in your level.
  2. That will also use the Datasmith through Interchange Framework that is not yet stable enough for production. The Datasmith > File Import route is still the recommended way for 5.5 and 5.6.
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