FINAL INDEX ON USB 2.2.4 VERSION REKORDBOX

Hi, i ve an issue. After having analyzed tracks , created playlist , exported track to playlist and finally exported playlist to usb device , i have a message error where rekordbox does not create final "library" ( i don t know english maybe it s INDEX) when i go to disconnct from devices section. So it means that i have trucks on usb under the folder created by rekorbox called CONTENTS , but when i go on rekordbox on ipad , remotebox told me that no index has been created.. I already created it before and so on.. all ok.. but now i m trying since 3 days but nothin.. usb is 16gb.. total music is 8gb .. .help hel help please.. thank you