If you are using ProductivitySuite 2.1 for ArcGIS for Desktop 10.0 to process your Ordnance Survey (OS) Integrated Transport Network (ITN) data, you may encounter a situation where the ConnectingLinks feature class is blank.
This is a known issue within the software and a hotfix has been released to address it. To obtain this hotfix please contact firstname.lastname@example.org.
Once the hotfix has been installed you will be required to reprocess your ITN data again from scratch, i.e. using the Data Converter and then the ITN Data Preparation tool.