Authorizing error -45054
I've just purchased a brand new Mac Book Pro - when trying to authorize the Mac book for my iTunes I keep getting an error detailing that it couldn't be done at this time. I've done it on the wifi at my work and at home. How can this be fixed so I can use my iTunes on my Mac? And will all my purchases be moved over as well?
iPhone 5s, iOS 7.1.1