Hi Arild Sundet
Thanks for reaching out. From your description, you’re able to enter your username and password, but when signing in to New Outlook for Windows, you receive a message saying "Something went wrong… You may need an app password", and I understand how confusing this is.
To let me guide you better, could you please confirm:
- Is the email account you’re trying to add an Outlook.com/ Hotmail/ Live / Microsoft account, or
- An account from another provider (such as Gmail, Yahoo, or an ISP)?
Meanwhile, please also confirm whether you can sign in successfully at Outlook on the web using a browser: sign in via https://outlook.live.com using the same account.
For further details, you can see these official support links:
- Add an email account to Outlook for Windows - Microsoft Support
- How to get and use app passwords - Microsoft Support
Looking forward to your reply so I can assist you further! Thank you so much for your understanding.