Error with the DDR SDRAM generated

Basically you've got a DDR controller but the DQS ports of the controller are not connected to the dedicated DQS pins on the Stratix II device.

Reasons for this:

1 - You haven't made pin assignments.

2 - You haven't actually connected the ports to the pins in your logic.

3 - You haven't connected all of the ports on the DDR controller to something useful and the logic for the datapath is being synthesized away.

Jake