And you too are only repeating what we already went through...luma 8.0 only works on B9S 1.2 if your on 1.0 or 1.1 you'll have to downgrade to luma 7.1 download link here, https://github.com/AuroraWright/Luma3DS/releases/download/v7.1/Luma3DSv7.1.7z
Extract Zip folder and copy the boot.firm to the root of your SD card. then go back to the 3ds.guide and look up how to update B9S to 1.2 before using luma updater again to re-download 8.0