Ok. So I noticed a little flaw in the whole B9S upgrade progress that may be confusing some newer, or less technical users. Basically, when people are copying over the new B9S 1.2 to install it, they are also copying over the new Luma3DS, which B9S 1.0 cannot boot. So it's defaulting to the CTRNAND payload and giving errors. There are 2 workarounds: (1) don't copy over the new Luma3DS until after you install the new B9S, or (2) load SafeB9SInstaller as the boot.firm and bypass Luma3DS. I'm writing this short guide to attempt to alleviate an incoming barrage of threads, all asking the same question. Instead of rewriting Plailect's guide, I'm going to slightly modify it. I will assume your 3DS is running Boot9Strap 1.0 (If you're on Boot9Strap 1.1, use https://transfer.sh/bi8b5/SafeB9SInstaller.firm instead of the SafeB9SInstaller from GitHub) and Luma3DS 7.x. -Go to the A9LH to B9S portion of Plailect's Guide. -Grab all the new files and complete steps 1 - 4. -After step 4, rename the 'boot.firm' you just copied over to your SD card to 'lumaboot.firm'. -Complete steps 5 - 9 -For step 10, you will be wanting 'SafeB9SInstaller.firm' instead of 'SafeB9SInstaller.bin'. Copy 'SafeB9SInstaller.firm' onto the root of your SD card, and rename it to 'boot.firm'. -Complete the rest of the steps in the first section. -Your SD card should be in your 3DS -Power on your 3DS. Don't hold any buttons down. -You will now see the SafeB9SInstaller. Follow the on-screen directions to install. -Once finished, before you press 'A' to exit, remove your SD card. (Failure to remove your SD card will result in SafeB9SInstaller rebooting back into SafeB9SInstaller) -Put the SD card into the computer (or use GodMode9 if you had it on your CTRNAND). -Delete the 'boot.firm' file on the root of your SD card. -Rename 'lumaboot.firm' on the root of your SD card to 'boot.firm'. -(Optional) Delete the 'boot9strap' folder on your SD card -Put your SD card back into your 3DS -Skip over 'Section II - Installing boot9strap' of the guide and continue with 'Section III - Configuring Luma3DS'. -Proceed with 'Section IV - CTRNAND Luma3DS'. -Skip over steps 3 - 5. -Skip over steps 13 - 14. -Before step 23, after you complete step 22, remove your SD card. -After you reboot, you will see the Luma3DS v8.0 configuration screen again. -Select your options. -Re-insert your SD card BEFORE hitting 'Start' to save your configuration. -Finish the rest of the guide. -Delete the 'hblauncher' folder on your SD card, if it exists.