CPLDFit fails with the an error message similar to the following:
"ERROR:Cpld:849 - Insufficient number of I/O banks. This design needs 3, but device only supports 2."
A common mistake is to assign I/O Standards using PACE or via Constraints Editor, and skipping some I/Os. When an I/O does not have an I/O Standard assigned to it, it will be assigned the default type as specified in the Project Navigator Implementation options. If this default is different from the other I/O Standards entered, it might result in the need for an additional I/O Bank.