Knowledge about errors while importing STEP and Solidworks files

I will paste here an exchange I had via email with the support team to share the knowledge

Chuck Welsh

Hello. I just looked at your two reports of STEP import crashing. One had the comment, Importing a Big Step Assembly originated from Solidworks 2019 .

The STEP file is badly corrupted. You can see this by opening it in Notepad and going down to line 8134 by searching for

#8134 =

#8126 = CARTESIAN_POINT ( ‘NONE’, ( 0.2306025344209833017, 30.61263303105040023, 63.90170538274460910 ) ) ;
#8135 = EDGE_CURVE ( ‘NONE’, #422095, #2817110, #3316250, .T. ) ;
#8134 = CARTESIAN_POINT ( ‘NONE’, ( -7997.814548649999779, 2346.25( |d ÅPrP g#Bš †£J T¢2É­ò oÄ ‰Óçei4 % ¯Û, ‡a xãá .Pà"C Æ~: i „{ü >¬¤eï @® iÌ* ¬ _!Ÿ¬”7!hàz vd`Å: G³LJ½ràÏ €L ü‰ÔÀ¤þ’SÊf€ay€Ø„
) Ó c

Everything afterwards is a mess. I was able to stop the crash in Rhino Version 7.1, but, of course, the result isn’t what you’re hoping for. Maybe compressing or emailing was the cause.

If you have any questions, or more information, about this STEP issue, please reply directly to me.

Thank you for taking the time to make these reports.


Ok, I have one question, why when I try to import the solidworks assembly, despite all parts being in the same folder, Rhino opens, the command line says successful but rhino is actually empty?

Is there a way to solve this kind of issue so the step file is not needed at all? The file I was trying to open was in the same computer, it was exported as step and imported from a local folder.

Anyways, thanks for taking a look into the issue.

Att. Altamiro A.J.

Chuck Welsh:

Hi. I’m the developer for STEP import and export, and am not very familiar with our Solidworks import. I’ve added John Brock of our technical support team to this reply. He should be better able to help with your question

John Brock:


SolidWorks assembly file have no surfaces or solids in them. That’s why ASM files are so small.
Basically, the assembly file is a list of part files, insertion coordinates, and transformations. Yes, the PRT files need to be in the same folder as the ASM.
When the assembly file is read, each PRT is read if it exists and added to the 3dm file.
File the PRT file is missing, and error goes by on the command line.
When the end of the ASM file is reached, Rhino reports the the file as successfully read.
That does NOT mean all (or any) of the referenced PRT files actually ended up in the Rhino file.

So the message is accurate. Perhaps if it said, “end of assembly file reached” would be better.




Is there any way I can export the LOG from the import ? That way I could see if there is any file missing from the folder that I did not identify via Solidworks.
However, I had some .prt files import as empty files too.
I agree that the message “End of Assembly File Reached” would be better suited, maybe even with some report like “X number of bodies/surfaces imported, Y number of bodies/surfaces failed or missing” Both for STEP and Solidworks Import.

Thank you for the amazing support as always.

Att. Altamiro A.J.

John Brock:

The messages are reported to the Command line so as soon as it’s finished, tap F2 to open Command History. Then you can copy/paste it.

BTW - This thread should have been posted to the Discourse forum so the next guy can find the information too.


Awesome, thanks!

I will see to make a post on the forum to share the info tonight, that way we can share the knowledge :slight_smile:

Att. Altamiro A.J.

So yeah, that’s it, I hope it can help someone

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