This computer is not authorized... but it is.

Repeated requests to authorize an already authorized computer for store downloads typically indicates you have corrupt or incomplete copies. Backup and then delete the tracks that won't play from your library without hiding from your purchase history. Redownload using the cloud links that should remain, or close iTunes and reopen if they don't show up straight away. While downloading click the activity widget and turn off the option that allows for simultaneous downloads.

If that hasn't helped see If iTunes for Windows prompts you to authorize your computer when you try to play purchases - Apple Support.

Unfortunately there isn't a way to validate every song in the library without playing them one by one.

tt2

Hey 0605-2021,

We see you're being prompted that your computer is not authorized to play music in iTunes, is that correct?

To confirm, did you take the steps below to authorize your PC?

• Authorize a PC to play iTunes purchases

If so, do only some songs play but not others? If this is the case, have you sourced your music from multiple Apple ID's? If you've used multiple Apple ID's in the past, you'd need to authorize the computer under each Apple ID for the songs that were purchased under it to play. You can do so by signing into your other Apple ID, then repeating the authorization steps.

Cheers!

Remove download and then download the songs

Yes. If downloading multiple tracks it may help to turn off the option for simultaneous downloads.

tt2