iTunes backup or iCloud backup allows Apple users to restore backup when they need it. In some cases iOS can not restore backup on Apple device and displays an error. It even be the case that you cannot see or select the most recent backup from the list of available backups in iTunes or iCloud. Another alert displayed by the iTunes can be “The backup [name]cannot be restored to this [iOS device] because the software on the [iOS device] is too old.” Or iTunes displays the alert message: “No backups available.” If you are unable to restore backup and encounter one of problems mentioned above, then there is simple solution for that.
When restoring an iOS backup to an iPhone, iPad, or iPod touch that is not using the latest version of iOS, you may see the above mentioned behaviors and here is the fix for that.
Update your device to the latest version of iOS to be able to restore the backup. iOS does not support restoring a backup from a newer version of iOS to a device using an older version of iOS.
For example: If you restore a backup from an iOS 7 device to an iOS 6.x or earlier device, you may not be successful.
Tips: If you want to transfer content from a device with a newer version of iOS to a device using an earlier version, do not use iCloud or iTunes backups. Instead, transfer the content from newer device to your computer, and then use iTunes to sync the content to your older device. Some content, including messages, app data, and other settings, cannot be transferred using this method.
There is an even better resolution and that is to use other tools e.g. iTools or iFunBox to take backups and to restore backups. Those tools will allow you to import/export data from device to computer and from computer to device. Importing and exporting data selectively will solve the problem and you won’t face iOS compatibility issues.