Fortbyte number 40 of the decryption challenge is waiting for you east of Fatal Fields. Be careful, you will have to equip yourself with the "Demi" skin to be able to retrieve the Fortbyte.
This outfit is available at level 87 of the paid version of the battle pass.
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The challenges and Fortbyte locations of the Fortnite Season 9 decryption challenge, as well as the complete list of Fortbytes, are to be found in this article.
