This error message appears if the design contains mixed voltages that require you to set the I/O Bank(s) VCCI voltage or VREF pins, or if you have assigned I/O macros to a region that overlaps an I/O Bank containing incompatible I/O technology.
Action
One or more of the following:
Assign more I/O Bank(s) with the required VCCI voltage
Assign VREF pins for I/O standards that require an input reference voltage and make sure these I/O standards are within the range of VREF pins. See Assigning VREF pins and Displaying pins in a VREF range for more information.
Change the I/O technology of the Bank, which the region is overlapping, to one that is compatible with the I/O macros assigned to the region
Move the region over the I/O Bank that has I/O technology compatible with the I/O macros assigned to the region