iTunes won't play song even though authorised
I am trying to play a song in iTunes Windows version and it comes up with a window saying the computer isn't authorised to play it and asks me to enter log-in details for a specific Apple ID to allow my computer to be authorised. I enter the log-in details requested and it then tells me that it's already authorised, but the song still won't play and simply comes up with the same window. What is going wrong?
Windows, Windows 10