[Galaxy Note5 Q&A, Help & Troubleshooting] JohnMonsour:
I've ran into this problem twice now either using .img to .tar tool that isn't set up properly with an incompatable version of stock rom or a corrupt dump of a stock rom or even using a proper stock rom. Or if you just so happen to accidently turn off O..E.M unlock... and your phone died or you restarted it.... Download mode spits out some red code usually or fails or even can complete but not in any case I've ever seen and boot sucessfully.... usually if you try to many times with odin you'll end up with a blue screen that comes up stating something went wrong during update process and to use Samsung's smart switch program on a pc. Only problem is at this point you've already tripped Knox and your warranty is now void so downloading smart switch and typing in your serial and one I will only give you another error stating that your phone is not comparable with smart switch due to Knox being tripped at 0x1......

At that point there are a couple options claim insurance if you have it, $200 or if you don't have insurance. Samsung will give you a spill about how your 1yr warranty is over and even if it isn't when they get your phone they will see your Knox status of 0x1 and tell you sorry your warranty is void due to end user tampering. So they offer a reflash for a cool $80 without warranty and that will reset your phone back to O.E.M specs with a Knox of 0x0 fix it for a mere $80. Smartswitch won't reflash firmware do to Knox being tripped. Sorry. You are more than welcome to try....*

COLOR="red"]NEVER, I REPEAT, NEVER TURN OFF O.E.M. UNLOCK UNDER ANY CIRCUMSTANCES IF YOU HAVE ROOTED YOUR PHONE, OR PUT A CUSTOM KERNEL OR FLASH A CUSTOM RECOVERY OR YOUR FAIL TO BOOT.[/COLOR]If you turned off O.E.M unlocking. Basically O.E.M unlocking is telling your phone it's okay that Knox is tripped. O.E.M unlock allows the skipping verified samsung signature checks on the first rom based bootloade rduring the boot sequence alowing it to bypass into the secondary bootloader and kernel.*

O.E.M. stands for "Original Equipment Manafacturer" i.e. being Samsung in this case so when you have not done anything to your phone when it comes brand new out of the package. Developer mode is hidden and unacessable for a reason.... O.E.M unlock means that in download mode you can flash unofficial code, i.e. C.W.M., TWRP, Other unsigned code from various developers. With no hassle due to Samsung being so kind to us developers and allowing us the option to manually unlock our bootloaders.*

Usually what happens specifically is Samsung has a secure bootloader which uses digital certificates to ensure that the software loaded before the operating system is trusted to boot the linux kernel shell we all know and love as android OS when you load a custom bootloader such as anything not signed by Samsung it fails to pass the signature checks and that's exactly what turning off O.E.M unlock did.*

But with us all being blessed with the option to manually unlock our Bootloaders through O.E.M unlock now so many options are open to us so as but not limited to.: Roms, MODS, Hacks, Busybox, Root, Xposed, Various Root Applications, Magisk, Kingoroot, GeoHots stuff, HashCodes stuff, even have the oppourtunity to create and test various of our own creations.*

Once upon a time Bootloaders were locked, meaning, No Roms, No kernels, etc, etc... Very, Very difficult to even root phone's. The reason I go into all of that is Because with great power comes great responsibility. Always back up your eds partition, and always always if you root and like to run custom rom Roms and all the development for this scene that only continues to grow and evolve Make sure you do one thing if nothing else and that is to read, read, read and know your phone inside and out. I am a developer and I work with software as much as I do hardware. I can afford to make mistakes as these aren't my daily drivers. I suggest if you like to unlock the full potential of your devices then please heed my warning about reading and knowing all the dos and dont's for what your devices is capable of and what will turn it into a very expensive paper weight. I'm not being a **** I'm trying to help. Because you have now tripped your Knox counter meaning it is permanently stuck in the state of your phone now having a void warranty and there is no going back.*

Once you turn O.E.M mode off you lock your bootloader and if you've already tripped Knox you can't flash a stock bootloader or Rom because your phone's hardware is preventing anything unauthorized from making it past the kernel checks..... clear some things up for You? I don't care the people say they have work around forCOLOR="red"]"custom binary frp lock"[/COLOR]because I have yet to see a phone recover. P.S. word to the wise that is one error you never, and I mean never want to see on your boot screen...

I came back from it once with a zeroed out serial number and a null one I. Once and that's a whole nother ball of wax. Claim warranty, play stupid if still covered if not Sammy will know so just shell out the $80 send it to them. They will reflash it and that's the end of that.