worst case

if the .wav file is not in the dir where your .mgu file is copy it there & rename as your .mgu and yeah it's not optimum but it will tell you if the file loads with the song

if you haven't tried it yet a reboot & opt > return all to factory settings may help

Lenovo YOGA 900 Window s 10 Home 64bit 16GB RAM\2018 13” MacBook Air casio wk7500 presonus audiobox i2 usb interface
casio wk-7500
biab & realband 2023 everything pk both with Current builds