The music would not show up in the player at all and everything was set up exactly how the instructions said.
I go to the developers website, register and submit a POST on the forum to ask for help after I saw that he has helped other users by logging into their accounts and figuring out what the issue was. I kept him up to date of different things I tried and the outcome and he simply told me he didn't know why it doesn't work and has no time to help at all.
Awesome customer service if I may say so myself.
For everyone who's interested in the true story: