Modified Android on New Handset?

[AC Question]

Hi, thought I'd come here as it seems to be full of Android experts!

I bought a Samsung Galaxy Mini S4 - GT-I9195I from eBay.

The phone was brand new, but not sealed and the phone had already been through the initial setup process, although all the new stickers were all over it.

However, when I try to update the handset, I get this message -

The operating system on your device has been modified in an unauthorised way. Try downloading software updates using Samsung Kies on your PC

Could this be down to apps that are installed? (Whatsapp, a Countdown game)? I have tried to use the Samsung software but get told after the latest update has downloaded that there was an error verifying it?

I'm really not sure if the phone has been hacked or not. Could this message be because the seller unlocked the handset? When I view the status of the phone in settings, everything looks normal although shaded out. It's on Android 4.4.4. Build no. KTU84P.I9195IXXU1AOD1

Hope someone can help.

Thanks

 

[belodion]

If you bought it as a new, unused device, return it for refund or replacement.