Issue:

ElumTools may generate an error message after invoking either the "Calculate Active View" or "Calculate Multiple Views" commands, using view(s) without visible geometry.


Workaround:

Invoke the Calculate Active View or Calculate Multiple View commands using only Views which contain at least one visible element.


Error Message:


Could not complete ElumTools command:  CalculateMultipleViewsCommandException:
Autodesk.Revit.Exceptions.ExternalApplicationException: Object reference not set to an instance of an object.
  at Autodesk.Revit.DB.CustomExporter.Export(IList`1 viewIds)
  at ElumTools.CalculateViewExportContext.Calculate(Document doc, IList`1 viewIds, String name, String description)
  at ElumTools.CalculateViewExportContext.Calculate(Document doc, IEnumerable`1 views, Boolean isolate)
  at ElumTools.CalculateMultipleViewsCommand.ExecuteCalculation()
  at ElumTools.CalculateBaseCommand.Execute()
  at ElumTools.ElumToolsCommand.ExecuteCommand(String& message, ElementSet elements)
  at ElumTools.ElumToolsCommand.ExecuteInternal(String& message, ElementSet elements)
  at ElumTools.ElumToolsCommand.ExecuteTransaction(ExternalCommandData commandData, String& message, ElementSet elements)
  at ElumTools.ElumToolsCommand.Execute(ExternalCommandData commandData, String& message, ElementSet elements)ElumTools 2018 Release 7 (2018.7.0.2)
RevitAPI
18.0.0.0
18.3.1.2C:\Program Files\Autodesk\Revit 2018\RevitAPI.dll