Switch 2 users report online console bans after running personal game “backups”

Earlier this week, the makers of the popular Mig Flash cartridge, which allows users to play Switch games loaded via an SD card without modifying the console itself, issued a firmware update enabling the cards to run original Switch games on the Switch 2. Since then, though, multiple Mig Flash users are reporting that they've seen their Switch 2 consoles banned from Nintendo's online servers, even in cases where the devices were only used to run backups of legitimate games the users purchased themselves.

"My Switch 2 test has been banned after using the Mig [Flash] with perfectly legal dumps of my own cartridges, so it would seem that Nintendo can detect something," popular hacking news account Switch Tools posted on social media Monday (along with a follow-up showing a stack of legitimate Switch games they said they had backed up using the device). "I strongly recommend that you do not use the Mig [Flash], it was already very risky to use but it is even more so on Switch 2."

My Switch 2 test has been banned, after using the mig switch with perfectly legal dumps of my own cartridges, so it would seem that Nintendo can detect something
Similar reports on reddit are starting to come in.https://t.co/nbPMlRWSaP https://t.co/3eq6dkbFMi
I strongly… pic.twitter.com/btzjQYJzE4

— SwitchTools (@SwitchTools) June 16, 2025

The insistence that the ban came while using "perfectly legal dumps of my own cartridges" is important here. Nintendo has long used certificates with robust cryptographic signatures to identify when individual copies of Switch games are being shared for the purposes of piracy. If Nintendo notices the same cryptographic signature on security certificates being used by hundreds of different consoles and accounts, for instance, the company can be relatively sure that all those users are engaging in piracy.

But the Mig Flash can also be used for backup and play of an individual's legal Switch game purchases on a personal console, which shouldn't lead to any such signature conflicts. On the Mig Flash website, the developers of the device say they "only support and guarantee your gaming with your own games backups. This applies to online, too. If you want to play online with the full Mig Flash warranty, you need to use your own dumped backups... Failure to respect this rule might end up in bans from Nintendo online service, which we won't be held responsible for."

At your own risk

Despite that "guarantee," Mig Flash users are now reporting that even running personal game backups on their own Switch 2 units has been enough to lead to a device-level ban from Nintendo's servers. "Just wanted to let everyone know to refrain from using their Mig Flash on the Switch 2 online for now," one Reddit user wrote. "My Switch 2 was just banned... Only games I had were my backed up games. Must be some new detection Nintendo has on these Mig Switches."

Other Mig Flash users in the same thread have reported similar bannings after running backups via a Mig Flash on the Switch 2. And in a separate thread, another Reddit user reported a server ban after trying "my Mig Switch in my [Switch 2] once. It didn't work. It just showed the game title and refused to load... Maybe it downloaded a flag for the console to be banned?"

Thus far, Nintendo seems to be limiting penalties for detected Mig Flash use to online server access. We haven't yet seen any reports of Nintendo completely disabling the offline capabilities of Switch 2 units, as the company claimed it could do in a recent EULA update (and as other console makers have long claimed as a possible penalty for hacking and piracy). Still, a server ban disables a wide range of Switch 2 features, including online play, GameChat, cloud saves, access to Switch Online classic titles, and the ability to download game and system updates.

For now, the main protection available to Mig Flash users who want to play game backups on their Switch 2 is to simply never connect their consoles to the Internet. But since that precaution mirrors the penalty Nintendo seems to be imposing in the first place, that "solution" may seem quite limiting to players who want a convenient way to back up their physical Switch games.