Currently, not all Stratix® III and Stratix IV device speed grades are supported by the UniPHY external memory interface debug toolkit.
In the debug toolkit Project Settings panel, the device speed grade is selected and then the Update Project Settings button is clicked.
The workaround is as follows for these device speed grades:
For Stratix IV -I1, -I2 use C2
For Stratix III -I2 use C2
This issue is planned to be fixed in a future version of Quartus II.