Anyone come accross this before? Sounds serious, but is it something I need to worry about?
Thanks,
David.
Try reinstalling the latest version of iTunes on your computer, you can get it here -> Apple - iTunes - Download iTunes Now
If that doesn't do it, you may be seeing something similar to what is described in this Apple doc -> iOS: 'Not enough free space' alert when trying to sync
I've been having the same trouble since updating to iTunes 11.1 and it is worse with 11.1.1. I have reinstalled iTunes and it didn't help.
What would be interesting is for you to restart holding the Command and R keys and using Disk Utility to check permissions. Mine has dozens of errors all in iTunes and it can not seem to repair them.
What I did was quit iTunes v 12.0.1. Open up the App Store and noticed I was not logged in. So I assumed the error was from the Apps it was trying to sync. I logged in to the App Store. Then opened iTunes and began the iPhone sync and it seems to have solved the problem.
Unknown error (-54) The iTunes Library file Cannot be saved
