What causes IfcConvert error "Argument is not a list of entity instances" ?

[ArnaudBBRI]

Hello,

I have received an IFC file, perfectly readable with blenderBIM.
I can run ifcConvert to OBJ with no problem like this :

.\IfcConvert.exe -y -j 16 --use-element-guids --y-up '.\AA.ifc' ./AA.obj

But when I run it to produce an XML

.\IfcConvert.exe -v '.\AA.ifc' ./AA.xml

Then I have the following error message:

IfcOpenShell IfcConvert v0.7.0-e508fb44 (OCC 7.5.3)
Scanning file...
Done scanning file
Parsing input file took 0 seconds
Writing XML output...

Log:
[Error] [2024-03-21 15:04:00] Argument is not a list of entity instances

What does the error message mean, and how can I avoid it ?

Thanks a lot,
Arnaud

[aothms]

Can you try running the file in python -m ifcopenshell.validate? Likely it will point you to the issue in the model.

[ArnaudBBRI]

Ok, found it with that python command!
Some non-optional empty attribute.

Thank you!