Same thing for me. I have an iPad 2 and got the -50 error. I had cloud synced my iPad with an album that i purchased on my mac. I unchecked "sync music" and then hit the sync button until it went through like others had reported. Just updated my itunes also to 10.3.1 and that also seems to work just fine as well. At least apple fixed this quickly.
I had the same problem with error -50 on both my IPhone 4 and Ipad. stopped by Apple store yesterday. I didn't have the update 10.3.1 so that was downloaded. We tried it again.
This time it just say can not backup the IPone, same with Ipad. It goes throw the prosses, it looks like it's working. But at the end, it say's - can not backup with NO error code.
In addition, when the Iphone is still hooked up to the computer. we can see the music, but, my hole library is GONE on bot my IPone and IPad. The Gentelman the Apple store suggested to restore my Iphone as if it is a brand new phone.
Have not tried it yet. Would like to know if anyone else is having the same problem.
I've also been hit with this problem since upgrading to iTunes 10.3.
Currently I'm on 10.3.1 (55), except I have a Mac Pro running 10.6.7 and no other devices (no iPhone, iPad etc), just the Mac. I do have an iPod though, and this syncs without any problems.
When I open iTunes I get the "An unknown error occurred (-50)" message.
When I try to anything to do with the iTunes Store I get the same again.
And when I try to log in to the iTunes Store, including to view my account, I get:
"We could not complete your iTunes Store request. An unknown error occurred (1008). There was an error in the iTunes Store. Please try again later."
Any suggestions welcome. Tried some of the above and no joy, especially as they mostly relate to people syncing with iPhones, iPads, etc.
In my case, I had the same problem only with my iPhone 4 (not iPad 2). I fixed it by going to the music tab in iTunes while the phone is connected and tuned off, and then on the sync voice memos. The list updated (I guess the list was outdated) and now my iPhone 4 syncs with no issues over WiFi. Hope this helps someone. By the way, I have iTunes Match also. Not sure how it affects non iTunes Match users.
My problem may be a bit different than others.
I have been getting this error since the update to 10.3+, however it's not happening when i'm syncing but rather when just listening to music. It continues to happen at any given time. Not even during a sync session, just while the iTunes program is running.
I'm running 10.5.3.3 on a windows7 enterprise box.
But mind you, i'm an audiofile and have more than 600GB of music, so i'm wondering if my library is corrupting do to the sheer size of the library.
Any help would be tremendously useful.
I don't see any pending problem as the application plays the music fine, but the error keeps popping up every 15 seconds.(give or take)