UTR Library Designer Error

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

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

16s rRNA Sequence : ACCUCCUUA

Desired Expression Range : 50002.55 ~ 1002672.55 ( Desired max expression should be smaller than 1000000 )

Number of expression-level intermediates : 16