If you are trying to use the Samsung Smart Switch utility app to copy your contacts, files, photos, phone log, and text messages, etc from an iPhone to your new Samsung Galaxy Core Prime..
..and in the process it says it can't do it..
could it be that the iPhone you are trying to transfer has iOS9?
On the Google Play Store description for Samsung Smart Switch, it says that the software is incompatible with iOS9, but is okay to use with all others iOS 4.21 or higher (link for reference)
Example using Samsung Smart Switch with an iPhone to Samsung Galaxy S5 Transfer content from your iPhone to Galaxy S5 CNET
*Note: if you had a bright idea to try to downgrade back to iOS 8.4, and create a backup copy of your data in iOS 9.. that iOS 9 backup won't be compatible trying to put it onto your new freshly downgraded iPhone with iOS 8.4.. so I wouldn't try that (link for reference)
On Samsung's Smart Switch official website, it says that if you use a OTG cable to make the switch between a computer to your new Samsung Galaxy phone it will work with iOS 9 (link for reference)
See Samsung's help instructions on how to transfer from iOS 9 to your Samsung Galaxy phone via OTG cable here:
(Note: as of this writing the images at the above webpage may not be visible. i alerted Samsung to fix this)
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