Cannot restore backup from iPhone 5 to iPhone 6

So i had an iPhone 5 and just bought a used iphone 6. I created i backup from my old iphone 5 on my hard disk (note: the iphone 5 was in iOS version 8.2 at the time of the backup) and proceeded to restore the backup to my new iPhone 6 (note: iphone 6 is in iOS version 8.3). Whenever i try to restore from the backup in itunes i get this message: "Itunes could not restore the iphone because the backup was corrupt or not compatible with the iphone that is beeing restored". I dont care about photos and such the only thing i care about are my contacts and im pretty screwed right now because my contact list is empty. And no i dont use iCloud. Any ideas??