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) : ATGCGTAAAGGAGAAGAACTTTTCACTGGAGTTGTCCCAATTCT

16s rRNA Sequence : ACCUCCUUA

Desired Expression Range : 1000000.00 ~ 1000000.00 ( Desired max expression should be larger than that of min )

Number of expression-level intermediates : 4