Why I can not update Samsung Galaxy note 3 software?

[Android Central Question]

Hello everyone.I am give up and very bad disappointed after all my try to resolve the problem with Samsung Galaxy note 3 software update.I have Samsung Galaxy note 3 with 4.3 originally bought.I never can update running software 4.3. Always telling me device been modified .Tryed watch videos and read but not any luck.Keep trying still but everything against me.Always come up something different when trying to install something from all the peoples advices found.Following step by step,but always accurse somewhere problem. Please please please any advices!would be so great full Remy

 

[Rukbat]

If the firmware has been modified, you can't update, because updating a phone with modified firmware can brick it. You first have to back everything up (see Backing up an Android Device and don't store the backups on the phone), then flash the stock ROM (see [Samsung] How to flash Stock ROM via ODIN) and if you're doing that, you might as well flash Lollipop. Then restore everything from the backups.