Yep. Seller previous has tripped Knox counter.
Which means that it likely has been either rooted at some point, or was running a custom rom. Or could have tripped it flashing a stock rom on to the device via Odin.
Chances are seller flashed a 4.4.2 stock rom onto the device before selling it, but it doesn't match the CSC (model identifier) and so OTA will not work.
Device CSC has to match the rom - you should however be able to update via Kies if you can get Kies to work.
If you can track down the devices CSC - you can always flash the proper stock firmware for the device and that would allow OTA updates in the future, but you will never be able to use Knox at this point and the device sadly has no hardware warranty because of Knox trip.