We use Dialux lighting analysis software, and in order to model the area to be illuminated we first need to import a DXF file from OpenBuildings Designer. However, the Dialux software we use only accepts older versions, such as DXF files generated from V8i or before, and does not seem to accept DXF files generated from OpenBuildings Designer CONNECT Edition. Is it possible to generate an older version of a DXF file?
Yes, when Exporting or Saving a DGN file to DWG/DXF format the Options dialog offers a range of versions. See this Wiki for more information. If you choose 2013 or earlier it should resolve the issue of importing a DXF file from OpenBuildings Designer into Dialux.