Encryption 6 (very close)

This challenge is the last encryption challenge i have and I only have one more app challenge and thats about it for me, and for this encryption challenge im pretty far. Infact I have a very good idea of it but im having trouble since i have a 27 and don't know how to deal with it.

try what is the most logical and u got it :)

its above and beyond the normal amount of letters, so maybe one needs to be subtracted? or something from everything

don't worry about that and continue to solve (since you are not quite done), it will become apparent