Why the error message is always the same

Whether the address is unknown or the password is wrong, you get the same message and the same code. A friendlier message in one of those cases would tell anyone with a list of email addresses which ones have accounts here.

The two answers also take the same time to come back, for the same reason.

If a message appears in Swedish

Every error these forms can produce has English text. A code we have not translated yet falls back to the Swedish sentence rather than to nothing, so you always learn what went wrong even when you have to paste it somewhere to read it.

The code above the message is the same in both languages. Quote it to support and they will know exactly what happened.