Ok keep in mind a playlist is a document file with a list of titles that point the player to the location of the songs. But if you move or delete the songs AFTER you created the playlist then the playlist won't work.

I presume your brother has the same log in to the computer as you do. If not, his song files might be in his personal account on the computer & inaccessible to you. That could explain why his playlist doesn't work when you open it.

My advice is that after downlding songs to keep them there or move them to a more permanent location BEFORE creating a playlist from them. A good permanent location would be one that has universal rights to all users on the computer. The admin of your comp, can set this folder up for you.