Description
Due to a problem in the Quartus® II software versions 11.1 SP2 and earlier, designs targeting Stratix® V devices will generate this error message if you assign a 2.5 V I/O standard input into an I/O bank that is powered by 3.0 V.
Resolution
To work around this problem until it is fixed in the Quartus II software, change the input I/O standard from 2.5 V to 3.0 V. When the fixed version of the Quartus II software is available, change the input I/O standard back to 2.5 V and recompile your project.
This problem is fixed beginning with the Quartus II software version 12.0.