Robert DiMauro, Bentley Technical Support Group
When exporting a file to IFC, the IFC Export dialog with mapping options for Map DataGroup Types and Properties displays the IFC Mapping items in red.
Check that the following file exists in C:\ProgramData\Bentley\AECOsimBuildingDesigner V8i Ss4\WorkSpace\BuildingDatasets\Dataset_US\data\classifications\IFC_2x3_Entities.xml
Go to C:\ProgramData\Bentley\AECOsimBuildingDesigner V8i SS4\WorkSpace\BuildingDatasets\Dataset_US\data\classifications\IFC_2x3_Entities.xml or to the location of your dataset data\classification\ folder to be sure that IFC_2x3_Entities.xml exists in it.