Simon

Thanks for the quick answer Martin! When I look the definition of the IfcAxis2Placement3D, the RefDirection parameter is optional and the "Attribute definitions" documentation says: If Axis and/or **RefDirection is...

Oh! I see! The IFC documentation is tricky sometimes, sorry. I tried to load the file into Solibri, Navisworks 2019 and SimpleBIM and all softwares displays the roof element correctly,...

Did you have the time to add the simple fallback?

Thanks for your quick reply! :) I tried with the last version on xbim-develop and I got another error:  

Hi Mikael, I tried to load the file with the lastest version of the xbim_master 5.1.427 version and I got the same errors. Do you have an idea? 

If it can help, I found that it's a regression bug 

Hi! Mr. Ouellette, Maybe I can help here, I guess have a similar issue ... When I export a model to IFC format, the color of the pipes in the...