UTR Library Designer Error

Template 5'-UTR Sequence (25NT) : NNNNNNNNNNNNNNNNNNNNNNNNN ,     Additional Constraints for designing 5'-UTR sequence (25NT) : NNNNNNNNNNNNNNNNNNNNNNNNN

Protein Coding Sequence (at least N-term 35NT) : ATGAGCACAAAACCACTCTTCCTGT ( Length should be more than 35NT )

16s rRNA Sequence : ACCUCCUUA

Desired Expression Range : 1002.55 ~ 102672.55

Number of expression-level intermediates : 16