Resolved in vCloud Director 9.7.x.
Workaround:
To workaround this issue you will need to split the process into two steps. Steps would follow:
Step 1 - Create a new Org vDC:
- Inside the vCloud director UI navigate to the Organisation you wish to use
- Under Virtual Datacenters click the green plus icon
- Go through the wizard and configure the Provider, Allocation Model, Storage Policies and Network pool
- On the page 'Configure Edge Gateway' leave the checkbox un-ticked
- Provide a name for the Org vDC
- Finish the wizard
Step 2 - Create a new Edge
- Go to the recently created Org vDC
- Navigate to 'Edge Gateways' tab
- Click the green plus button to add a new Edge
- On the first pane, tick the box labeled as 'Sub-Allocate IP Pools'
- Proceed with the configuration until completion