Preamble

If you've searched around this subreddit even a bit, you may be aware that the aforementioned guides are NOT suggested by this community. In fact, having the negligence to admit having a struggle with something when you haven't used the suggested guide is a good way to get downvoted. Are they wrong for being unforgiving to users who fail to follow their wiki and FAQ's? Not particularly. But, maybe you're like me and scared/stressed by the idea of restarting everything from scratch (^{my "RCM jig" barely works and I'm terrified at such an idea because I'm worried I'll lose my AutoRCM}). Regardless of your reasoning, you and many other people (as my research from my own endeavours to solve this problem has made abundantly clear) just don't want to start over; fortunately, I can tell you a simple method that won't require you to.

Set-Up Check

Naturally, we first need to ensure that you are doing everything else correctly: this "solution" won't fix your problem if your problem isn't what this guide is meant to solve. There are 3 main parts here that should be checked:

1. Are Atmosphere and Hekate up to date? You can see Atmosphere's version in your Nintendo Switch's System Settings; Hekate's version is displayed at the upper-left corner of the Nintendo Switch's screen after injecting its payload: if either of them are outdated, you should return to your original guide's page on updating CFW to fix that.

2. Are your "sigpatches" properly applied? Atmosphere is built with a precautionary measure that blocks unnatural titles from being installed to protect uninformed users from making unsafe mistakes or something. But, because that's precisely what we -- as informed users -- want to do, we'll need these "sigpatches" to circumvent this. You most likely will find links to these files in one of this subreddit's sticked threads.

3. Is Tinfoil properly set up to install? From Tinfoil's site, you should have grabbed the "Self-Installer" build -- not the "Applet Mode" or "NSP" equivalents; the folder said download should contain is one named "tinfoil" containing "tinfoil.nro" among other things and you'll want to put it directly in the "switch" folder on your Switch's SD Card.

The "Solution"

Assuming you've properly adhered to all provided instructions, you probably don't understand why Tinfoil just won't install -- your set-up is ALMOST just like that of a user who followed this community's suggested guide. The key difference between that guide and the guide you used is your payload: your guide injects Hekate to boot Atmosphere while that guide injects fusee to boot it. Why this matters is because, from what I've heard, Hekate does not properly apply sigpatches. So, you'll need to boot "fusee" to load Atmosphere instead. Fortunately, Hekate allows you to easily boot other payloads from itself. To do this, download the latest release of fusee.bin (which releases alongside updates to Atmosphere and, thus, is found on Atmosphere's Github page's releases) and put it directly in /bootloader/payloads; inject your Hekate payload as usual but instead tap the large "Payloads" button (the second large option from the right side of Hekate's top menu) and select "fusee.bin." Now, attempt to install Tinfoil once more (if there is a failed installation attempt leftover from previous efforts, be sure to delete it through the options menu on the home menu accessible through the (+) button). If it worked, celebrate! YAY!!!!!!!!!!!!!!

Things to Remember

Every time you want to play around with unnatural titles, you'll need to inject that "fusee.bin" again: failure to do so, even after prior successful installation, will lead to the Switch saying that your unnaturally installed titles are "corrupted" and it will refuse to run them. But, don't worry, all you have to do to fix this is inject that payload again and then allow it to go through its process of checking for corruptions -- as long as you booted Atmosphere with that payload, it'll find none and remove the error peacefully.

I tried multiple times last night to download and extract Tinfoil but the NRO is the only thing that won't extract properly. I've installed sigpatches, tried different versions, and looking around forums for help to no avail. I've seen people say to use DBI, but I heard the dev was adding malicious code into newer versions so I'm a bit worried to use that, plus I can't read Russian. Is it an issue with tinfoil itself, or could my PC possibly be blocking the file? Any help would be appreciated.

I have no idea why tinfoil is not downloading for me. If I try to use Tinwoo and install the Tinfoil Forwarder it fails the installation (error 0x0001fb402). While if I try to download the NRO self installer from the og tinfoil website i still get an error when i try to launch it from album. I have no idea what to do from here, someone help!!

P.S. My Switch is V1, I use EmuMMC and i am new to switch modding 😔💔

UPDATE: Tysm for your kind help!! I was able to download the syspatches needed to make it work!

Managed to boot into Atmosphere via fusee and tigrarcm. I have put the tinfoil folder with tinfoil.nro in the SDcard /switch folder but no Tinfoil appears on the homescreen and its not in the Album (goldleaf and daybreak are in there but I have never used them). Any ideas?

I have updated my sigpatches using the ones at https://sigmapatches.coomer.party/ and injected fusee.bin from https://github.com/Atmosphere-NX/Atmosphere/releases/tag/1.6.2

but when i go into the homebrew menu through the album icon and run the Tinfoil Self-install it get this error. It still eventually shows an icon for tinfoil and asks me whether i want to star tthe software but its really annoying.

Am i doing something wrong?

I also tried updating my sigpatches with this https://github.com/ITotalJustice/sigpatch-updater/releases

just to be sure, but it still gives the same problem.

I'm on Atmosphere 1.6.2 with HOS firmware 17.0.0

EDIT: Figured it out, my OFW had a linked nintendo account. I used Linkalho to unlink and now its working fine!