Why won't my phone update?

[AC Question]

I bought a Galaxy s4 off ebay. The seller said he purchased it brand new in Finland and didn't ever use it. As far as I know it is factory unlocked and has never been a carier phone. When I try to update it I get this "your device has been modified. Software updates are not available." There isn't an SD card in it, I tried rebooting and clearing cache but still having the same problem. Another thing I have notice when turning the phone on is "Set Warranty Bit : Kernal" is displayed in the top left corner on startup. Can anyone help me with this?

 

[Rukbat]

Since it wasn't sold by your carrier, the firmware in it isn't the firmware that should be in it as far as your carrier's update program is concerned. You'll have to go to the S4 forum for your carrier on XDA Forums, find an update for your model phone and install it manually (there are usually instructions in the first post in the thread - if not, and the update is Odin-compatible, see [Samsung] How to flash Stock ROM via ODIN [whether you're getting a full ROM flash or just an update is determined by the file - you do pretty much the same steps for either one]).