Hi Vegard! Could you try uninstalling the app, restarting your device and reinstalling the app? Also, try adding the account if you know the credentials. If you don't, you can try recovering it by following the steps in this link: https://goo.gl/7TnbYx . Let us know if it helps!
Also, we noticed that you shared your email address over screenshot publicly to help with your issue. Since emails are often considered private information we would recommend deleting your tweet since this information is personal.