Unable to download songs in Apple Music with error and synchronise issue with the map

I have download several albums/songs in apple music (with apple subscription) but when i want to upload to another device the map "apple music" is empty. And when i want to download the misic in apple music i get the code 7506. Also when i open apple devices and select my ipod i cannot get the songs on my ipod. when i open the map then the computer also cannot find the songs and . I've tried several things as restart the computer, delete apple music and a new download of the program. What can i do to let everything work properly as it used tot be?

[Re-Titled by Moderator]

Original Title: I have an 7506 error when i download songs in apple music and cannot synchronise albums/songs with the map "apple music"