If you’re a heavy AirPlay user, and you use older hardware such as the original AirPort Express, you may want to hold off on the latest iTunes update. Screenshot of error below:

[Edit: additional details]

Hardware: AirPort Express 802.11n (1st Generation)

You may click here to view the product description on Amazon, but we DO NOT recommend buying one!!
Model Number: A1264
Order Number: MB321LL/A