Dataprep crashes editor

For the whole day I have been fighting with the problem, and I just don’t know where to write except here.
I am trying to import a datasmith file into my project using dataprep.
I create a dataprep file, import the datasmith file into it and everything works fine so far. If I press “Execute” it works, but if I press “Execute” again(or “Commite”), the editor will freeze. In the task manager, the load of the RAM by the editor increases until it reaches 96-97%. The editor hangs for 10 minutes, and then crashes without any error messages.
I ran some tests, and realized, that everything was working fine in the new project, but it was crashing in my work one. How to understand what exactly is the problem? The project is huge, I have no idea what this might be.
Any ideas?
I attach a log for the caseUE_01.log (96.7 KB)

I’m facing similar issue! Always on commit at 84%. It says finalising and then it crashes, but my editor crashes instantly it doesn’t hang. I noticed this only happens when there is an instance of the datasmith scene in the level (it spawns automatically after every import so if you don’t do anything it will crash on the first Reimport).
When I delete the datasmith scene actor and run dataprep again no issues, it spawns a new one. But this is a problem because it doesn’t save any changes you make on Unreal (materials / position… etc) so you have to make all the changes outside of unreal, or redo the changes after every import. I hope someone can give us a fix to this problem.

Let me know if you find a solution to this! I’m still trying to figure it out.

Which version of the engine are you using?
What format are you importing? udatasmith?

I’m using UE 5.0.2 and I’m importing a udatasmith file. I have produced the file with revit 2020 and revit 2023 and I’m getting the same issue. I also tried reimporting with different scenarios to see where the issue is. It seems like only the original datasmith scene produced by dataprep is causing the crash. I found a weird workaround: If I select the whole imported heirarchy and create a level instance, I can then Reimport with no issue. I just have to make sure I save the instance with the same name after every reimport, then delete the newly spawned one. That way I am left with however many instances I want for the building, and it doesn’t crash the editor. I hope this narrows down the problem.

Please let me know if there is a better practice to deal with this issue. Or if there is any possibility to keep the changes made in unreal after every reimport, I would like to know how.

Thank you for your time!

@UE_FlavienP I transferred my file from UE 5.0.3 to UE 5.1.0 and I have run into another problem with Dataprep crashing the editor. I use the dataprep to import datasmith files from Revit 2023. I recreated the problem on a blank UE 5.1 project and found that the “substitute material by table” node is the thing that crashes the editor. The crash only happens when I try to parameterize the material data table (right click > link to parameter > create new parameter) = instant crash. It used to work with 5.0.3 and I created multiple instances of this dataprep asset. In 5.1.0 the Dataprep asset and all its instances crash the editor whenever I run/open/double click, so I can’t even edit it (because it was transferred from 5.0.3 and contains the paramaterized material data table)

Please let me know if there is an alternative or a solution to this issue

Okay, I reproduced, thank you for reporting that. I added it into our bug tracking.

Do you still have access to your 5.0.3 version of the dataprep asset?


I have a similar problem when using data prep and the substitute by material table in 5.1 (blank project, skup datasmith file). Crash happens when I commit the import.

been having problems with data prep assets. it worked just fine the first time I used it and now it just crashes every time I attempt to import datasmith file from revit… am running UE 5.1 and Revit 2023. please please help am trying to present a project on Thursday.


You do not seem to be using “link to parameter”, do you?
You are commiting on a recipe with a substitute by material?
Can you share logs?

I need more details on what you are doing:

  • which nodes are you using?
  • is it crashing when you click import? when you execute? when you commit?

Can you share logs?

Having this exact same issue as @DOPC mentions, i was working fine for several hours, then data prep all of the sudden just keeps crashing now, i’ve tried deleting intermidiate files, saved files and nothing it just now all of the sudden wheneber i try to import any datasmith files from revit to data prep - it crashes right when it says updating 3d view port.

Can you guys checked it is not link to the bug described there:

Running dataprep will modify some assets (that should not happen) and when closing project if you save those assets they will be removed from the engine content. Any subsequent dataprep import will then crash.

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Ok so quick update, using UE5.1.0 - So I uninstalled then reinstalled engine and dataprep worked fine once - when closing project and dataprep asks that nothing was commited and asks if you still want close then clicked on yes - data prep from there is completely broken, and i can’t no longer import any datasmith files unless reinstall engine. please can someone look into this.

Can you check this thread: Visual Dataprep Viewport Crash - #2 by UE_FlavienP

Do you have the assets in the dataprep content folder?

Confirming that this is the bug happening for me, for now the workaround mentioned works for me. I verified UE as mentioned and now i only have to uncheck the dirty marked assets in choose assets to save option. For now this works for me, The first crash bug you posted, Thanks @UE_FlavienP