[Galaxy Tab S2 General] OhioYJ:
So as many have found out the latest builds of Lineage require updating the firmware on our tablets. Even as a Linux user I found this very frustrating and ran into many problems actually, so I figured I'd do a quick guide.

I take no responsibility for anything that happens by following this guide, use at your own risk.

Heimdall is honestly just finicky in my opinion, and if you don't have all the "pieces of the puzzle" in place it's not going to work. It works easier in Linux in my opinion so even if you aren't a Linux user, I would still use a flash drive to temporarily boot into Linux to flash this. This method however will prevent you from having to wipe your tablet.

To create a bootable Linux flash drive you can use Unetbootin, which you can download for free here (Your other option would be to burn the ISO straight to a DVD and skip the unetbootin step):

https://unetbootin.github.io/

For Linux, I'm using Linux Mint Cinnamon, You can download for free here:

https://www.linuxmint.com/download.php

Then run unetbootin (yours will look a little different, I'm running it in Linux):

Point it to the Linux ISO, and tell it where an empty flash drive is. It will erase everything on the flash drive. Afterwards you can load whatever you want on the flash drive. However be aware when booting Linux from this drive you can't access what is on the drive (at least not by normal methods).

After this has successfully completed, reboot the PC, and boot from the USB drive. Your PC will boot into Linux.

Next we need to install heimdall program. You need to open up the "start menu" and open the "synaptic package manager". You can find this stuff in the menus, however the easiest way to get to these items is to just start typing the name of the item. See below:

Search for heimdall, click all three boxes, choosing install on each, and then click apply. It's that easy it will download everything that's need and install. If heimdall does not show up just click reload. Note you will need internet for this to work.

Note you need heimdall version 1.4.2 for any of this to work. It's very likely that the version in synaptic was not version 1.4.2. If it was not. Go to the site below, scroll to the bottom and download, heimdall-flash_1.4.2-0ubuntu1~17.10~ricotz1_amd64.deb

https://launchpad.net/~ricotz/+archive/ubuntu/unstable/+build/13609401

This heimdall-flash_1.4.2-0ubuntu1~17.10~ricotz1_amd64.deb by default will be in the home folder under downloads, and is an installable file. Install this. Ignore the warning about an older version being available in Synaptic.

Time to open up a terminal window:

As this point I'm going to assume you already have your necessary files. I have a US tablet, and I did use the Canada file from SamMobile if that helps anyone. To get the files needed unzip the Tar.md5 file from the zip file you downloaded. Then remove the .md5 from the end. Now you can open the .tar and extract all these files. I placed all these in folder on my Desktop for ease of access.

To flash these you will need to be in Download mode. You can enter download mode by using the reboot menu, entering through TWRP, or Home + Volume Down + Power when powering the tablet on.

You will need to navigate to this folder for flashing. "CD" changes directory, "LS" lists files in the directory. Capital letters matter. I put the files in a folder called temp on my desktop so in my terminal I end up with something like this:

Now thanks to [MENTION=5227588]Deltadroid[/MENTION] we know what to flash, copy and paste this into the terminal window.

sudo heimdall flash --SBL1 sbl1.mbn --ABOOT aboot.mbn --RPM rpm.mbn --TZ tz.mbn --HYP hyp.mbn --SEC sec.dat --KEYMASTER keymaster.mbn --CMNLIB cmnlib.mbn --DSP adspso.bin --MODEM modem.bin --APNHLOS NON-HLOS.bin

Even with this updated, you can still boot into your old Lineage install. However you are also now free to update to the latest nightlies now.

Once you are done, choose shutdown and remove the USB, and your PC will boot back up as normal.

Any questions, ask, don't get yourself in trouble. Flashing firmware can be serious.