ID:13634 VHDL warning at <location>: ignored choice that is null range

CAUSE: In a VHDL Design File (.vhd) at the specified location, you used a choice that is a null range. A choice cannot be a null range; therefore, Quartus Prime Integrated Synthesis ignored the choice.

ACTION: If you do not want Quartus Prime Integrated Synthesis to ignore the choice, or to avoid receiving this message in the future, change the choice so it is not a null range. Otherwise, no action is required.