On version: 3.3.7165 Store
All the menu options:
Help > Support > View Settings File
Help > Support > View Last.fm Scrobble Log
Help > Support > View Error Log
end with the same issue. Notepad opens with the error "The system cannot find the path specified".
It is probably something to do with how the Microsoft Store installs apps in a non-standard location.
On my device (for anyone who find this forum post), the files should be at C:\Users\<username>\AppData\Local\Packages\<unique ID containing the word MusicBee>\LocalCache\Roaming\MusicBee.