Just Copied and Pasted from the post u/FailedShack made found here.

Last updated on 07/03/2019.

New thread to allow people to leave comments since the other one got archived.

As you may already know, Wii U USB Helper has been discontinued, however, this shouldn't mean we're not allowed to use it anymore.

So I've made a launcher which makes it work again. Hooray!

Here's how to set it up:

Step 1 - Download the installer.

Step 2 - Run it and follow the on-screen instructions.

Step 3 - When asked, use this title key site: titlekeys.ovh

You may find it easier to follow this video guide.

Now on GitHub! Join us on Discord.

If you used Wii U USB Helper before it was discontinued and have an old version lying around, please PM me.

I'm trying to keep a spreadsheet of preserved Wii U USB Helper versions. Thank you!

News

Nintendo 3DS games cannot be downloaded with Wii U USB Helper or any other tool that relies on Nintendo's servers to download titles without proof of purchase.

As of system update 11.8.0-41, the 3DS sends new required title information in download requests to Nintendo's servers, which includes the title's ticket. Tickets are signed and cannot be feasibly forged, they also contain data such as original console id, which means that if shared, they can easily be blacklisted and the console of origin banned. Similar to Nintendo Switch per-console certificates. https://www.3dbrew.org/wiki/11.8.0-41#nim

Known issues

• Certain virtual console platforms' channels are not extracted properly, resulting in corrupted roms. This is Wii U USB Helper's fault and there's not much that can be done.

Troubleshooting

Wii U USB Helper gets stuck at 'Preparing ticket cache'

Right click the launcher's tray icon in the taskbar and go to Advanced -> Clear Install. Then restart your computer and try again.

Error when trying to change the title keys site

For technical reasons it's not possible to change the title key site from the button in Wii U USB Helper itself, if you've done this unknowingly, simply force close Wii U USB Helper from the task manager. Then start it from the launcher again.

Why does Wii U USB Helper still say 'Wii U USB Helper has been discontinued'?

To avoid overwriting an already exisiting install, the launcher will only apply the workaround required for Wii U USB Helper to run if no previous install is found.

To fix this, while the launcher it's still open, find the notification icon for the launcher in the task bar, right click it and go to Advanced -> Clear Install.

None of the above suits me and I use Avast or AVG

Avast and AVG have been known to conflict with the launcher, causing issues such as the title key site not being accepted or Windows suddenly wanting to restart. If you experience either of these issues, try excluding the launcher's folder, if that doesn't help, try disabling the antivirus entirely. Afterwards please fill this poll.

I have an issue that's not listed here!

While the launcher is still open, right click its notification icon on the taskbar and select 'Report Issue'.

This will generate a debug message and save a link to it in your clipboard, PM it to me.

FAQ

Why is the launcher being detected as a threat?

It appears the launcher is now being flagged as a trojan in Microsoft Defender and other antivirus software due to bad heuristics. I've already submitted it as a false positive. Exclude the Launcher for the time being.

Please read this article for more information.

This is a nuisance to other small developers as well.

Why do we need this? My Wii U USB Helper is working fine.

Newer 'discontinued' versions of USB Helper will allow you to continue using them as long as it finds files of a previously available install. So, for all intents and purposes, they are a ticking time bomb, because if you move to another computer, or your install gets removed, you'll not be able to launch them anymore.

You can download a patched version of Wii U USB Helper Go! for Android here.

You can download a copy of the latest Wii U USB Transfer Tool here. Mirrored GitHub repo.

The writeup I promised when I first released the launcher is finally out!

We now have an official Discord server for assistance and discussion!