Nintendo dsi an error occurred?

Moin, I wanted to play Nintendo again, but when I want to start the card "Alex Rider Stormbreaker THG" only this comes up:

(Looks dirtier than it is xD).

So either this is one of the R4i3DS cards that can play hundreds of games on one card and it no longer works because you have made a software update. For that you would have to hack your DSI. If that's the case, take a look at the ModernVintageGamer YouTube channel.

If it's a legal card, just clean it up with cotton swabs. Unscrew the latter and clean the inside. Worst case → DSI can't read the card because the card reader is defective. Exchanging is very, very tricky. Then better buy a new DS.

Yes it is probably a map like the one mentioned above xD maybe you have a link to the video where it is explained? I don't think so.

Yes look for ModernVintageGamer DSI. Wait, I'll give you the exact name of the video. But it's best to make a backup of your data and I guarantee nothing. Here you go: Another look at the Nintendo DSi in 2019 - Softmodding, Homebrew and DSIWare | MVG

Blowing it in is the worst thing you can do because it oxidizes the contacts more.

Bruh. How long does it take I have had my DS since 2010 and have always blown in xD. Ok, I'm annoying you just think. Yes're right. But I still do it and still recommend it. Haha

Take the cardridge apart and go over the golden contacts with an eraser.

Most of the time, an oxidized surface forms on the gold contacts.

Congratulations, you have helped your card to oxidize faster due to the increased humidity in the air you breathe.

In case you don't know what oxidizing means, Wikipedia has a nice article about it.

I know what that is. His problem is (if you've read my answer) that he's using a card that Nintendo doesn't like. He would have to pull through a softmod so that his DS accepts the card. He may have updated it…

Can I start the DSi without a game or with another game inserted?

Yes. Only the flash card does not work.