ID:18867 Clock Region assignment for signal <name> is invalid: "<constraint>". Refer to the Information pane in the Assignment Editor for details on the legal syntax for this assignment. For this device, the maximum allowed sector coordinate is "<max_sector>"

CAUSE: A Clock Region assignment was specified for this signal, but the value of this constraint is invalid.

ACTION: Refer to the Clock Region help within the Assignment Editor for a description of the legal values for this assignment. Also ensure that the coordinates specified for this setting align with the current device bounds.