PR: NullReferenceException when trying to export curtain system with base quantities

[andydandy74]

Problem Description

When trying to export a curtain system with export seetings to include base quantities the addin throws a NullreferenceException. The file is still exported, though.

Journal snippet

  'C 05-Feb-2024 21:19:06.739;   1:< IFC error: Exporting element "AA_337_AW-FAS_PfostenRiegel_100.0 x 200.0",2779 - System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
  '   bei Revit.IFC.Export.Exporter.PropertySet.Calculators.HeightCalculator.Calculate(ExporterIFC exporterIFC, IFCExportBodyParams extrusionCreationData, Element element, ElementType elementType, EntryMap entryMap)
  '   bei Revit.IFC.Export.Exporter.PropertySet.QuantityEntryMap.ProcessEntry(IFCFile file, ExporterIFC exporterIFC, IFCExportBodyParams extrusionCreationData, Element element, ElementType elementType, QuantityEntry parentEntry)
  '   bei Revit.IFC.Export.Exporter.PropertySet.QuantityEntry.ProcessEntry(IFCFile file, ExporterIFC exporterIFC, IFCExportBodyParams extrusionCreationData, Element element, ElementType elementType)
  '   bei Revit.IFC.Export.Exporter.PropertySet.QuantityDescription.ProcessEntries(IFCFile file, ExporterIFC exporterIFC, IFCExportBodyParams ifcParams, Element elementToUse, ElementType elemTypeToUse)
  '   bei Revit.IFC.Export.Utility.ExporterUtil.ExportElementQuantities(ExporterIFC exporterIFC, Element element, ProductWrapper productWrapper)
  '   bei Revit.IFC.Export.Utility.ExporterUtil.ExportRelatedProperties(ExporterIFC exporterIFC, Element element, ProductWrapper productWrapper)
  '   bei Revit.IFC.Export.Exporter.Exporter.ExportElement(ExporterIFC exporterIFC, Element element) 

Steps to reproduce

• Open the model (https://github.com/andydandy74/MyIssues/raw/master/RevitIFC737/155_IFC_CurtainsystemException.rvt)
• In the IFC export dialog make sure that "Base quantities" is unchecked
• Export and observe there is no issue
• Export again, this time with "Base quantities" checked and notice the warning.

Revit Version

2024.2.0

IFC for Revit Addon Version

24.2.0

Windows Version

10 22H2

[AngelVelezSosa]

We have identified the issue and will try to include a fix in a future update.

[andydandy74]

This looks fixed in 24.2.20 - thanks!