When you try to download content you bought from the iTunes Store, you might see a message that says "There was an error downloading your purchased music. An unknown error occurred."
To fix the issue, check for any issues with third-party security software and remove the cached download file. Then try to download the music again.
Fix issues with third-party security software
If your connection times out during a download, it might be caused by security software monitoring certain servers and common ports. If your third-party security software doesn't let you download from iTunes, learn how to fix the issue.

Remove the cached download file
A network issue can also cause an iTunes download to time out. When this happens, a cached download file might not let you download the file next time. Remove the cached download on a Mac or PC before you try the download again.
On a Mac
- If iTunes is open, quit the program.
- In Finder, select Go > Home from the menu bar at the top of your screen.
- Open Music > iTunes > iTunes Media. If you have an older iTunes library, you might see an iTunes Music folder instead of an iTunes Media folder.
- Open Downloads.
- Drag all files from the folder to Trash.
- Open iTunes.
- From the menu bar at the top of your screen, choose Account > Check for Available Downloads.
- If prompted, enter your Apple ID and password.
- Click Check. Your music downloads to your iTunes Library.
On a PC
- If iTunes is open, quit the program.
- Press the Windows key on your keyboard. If your keyboard doesn't have a Windows key, press the Control (Ctrl) and Escape (Esc) keys.
- Click on the magnifying icon or search field.
- In the search field, enter
%USERPROFILE%\Music. - Open iTunes > iTunes Media. If you have an older iTunes library, you might see an iTunes Music folder instead of an iTunes Media folder.
- Open Downloads.
- Drag all files from the folder to the Recycle Bin.
- Open iTunes.
- From the menu bar at the top of the iTunes window, choose Account
Store> Check for Available Downloads. - If prompted, enter your Apple ID and password.
- Click Check. Your music downloads to your iTunes Library.