Due to a problem in the Quartus® II software versions 11.0 and earlier, when targeting Stratix® V devices, the ALTIOBUF megafunction is unable to create output files when implementing dynamic output delay chains if the output buffer dynamic delay chain1 or output buffer dynamic delay chain2 options are enabled.
In the Quartus II software on Windows, you will see a clearbox.exe error.
In the Quartus II software on Linux, you will see the following error message:
"Fatal Error: Segment Violation at (nil) Module: qmegawiz"
To work around this problem, set the output delay chains statically using the Assignment Editor.
This problem is fixed beginning with the Quartus II software version 11.0 SP1.