This warning will be generated for designs using Cyclone® V devices in the Quartus® II software version 13.0sp1 when using differential and single-ended I/O standards in the same I/O bank. However, this warning may also be generated by mistake for banks that only contain single-ended I/O pins.
The warning can be ignored if there are no LVDS, RSDS, or mini-LVDS signals in banks containing only single-ended I/O standards.
The critical warning is scheduled to be fixed in Quartus® II software version 14.1 so that it is only generated in valid cases.