UTR Library Designer Error

Template 5'-UTR Sequence (25NT) : AGTGATAGCGGTACCAATTACAAAGAACACGGGGGAAGGAGGTTAAAC ( Length should be 25NT ) ,     Additional Constraints for designing 5'-UTR sequence (25NT) : NNNNNNNNNRRRRRRRRRNNNNNNN

Protein Coding Sequence (at least N-term 35NT) : ATGAAAAAAAGAAAGAGGCGAAACTTTAAAAGGTTC

16s rRNA Sequence : ACCUCCUUU

Desired Expression Range : 1002.55 ~ 502672.55

Number of expression-level intermediates : 16