Error 4521?

i have the same problem but it comes up error 4220.

I keep getting error 4251, but I suspect it's basically the same thing ... iTunes, or at least the latest version of iTunes, appears to be incompatible with some Dell computers. I guess Apple does what Microsoft does - throw something out there and let the users Beta-test it.

I'm not sure what the actual error is, but I've found that if you change the burning settings it can sometimes help.

Go to "Edit" > "Preferences" > click the "Advanced" tab > and then the "Burning" tab.
Then lower the preferred speed (say, from 24x to 16x) and change the gap between songs from two seconds to none.

Since doing this I've only had the error come up a couple of times in which case I just lowered the speed once again.

Hope this helps 🙂