An app says "401" or keeps asking for your password

Your calendar app, contacts app, DAVx5, Thunderbird or a network drive shows the error 401, Unauthorized or incorrect password, or keeps asking for your password again and again. While logging in via the browser works fine. This is almost always caused by two-factor authentication.

Why does this happen?

With a WebOké Nextcloud, two-factor authentication is always switched on: after your password, Nextcloud asks for a code. A calendar app on your phone can't enter that code. That's why Nextcloud doesn't accept your normal password in these kinds of apps. You need an app password: a separate password for one app or device.

How to fix it

1. Can the app log in via the browser (the login flow)? Then use that. You log in in your browser with a code, and the app automatically gets its own password. This is how the Nextcloud app on your phone, the Talk app, the desktop app and DAVx5 work.
2. Can't do that, as with the calendar on the iPhone, the Mac or in Thunderbird? Then create an app password in Nextcloud and use that instead of your normal password. You can read how to do this in App passwords: when and how to use them.
3. Enter the correct address of your Nextcloud in the app, and your username. If it doesn't work with your e-mail address, use your username instead.
4. Still not working after that? Remove the account in the app and add it again with the app password.

It always worked and suddenly it doesn't anymore

• Have you revoked an app password, or wiped a device remotely? Then that app needs to log in again. See Viewing, revoking, or remotely wiping devices and sessions.
• Has the address of your Nextcloud changed, for example to your own domain? Enter the new address in the app. See Moving your Nextcloud to your own domain: what do you need to update in apps afterwards?.
• Is your address being throttled? An app that keeps trying with an incorrect password makes Nextcloud slow you down in the browser too. See Can't log in: code, password or rate limiting.

You can read how to set up your calendar and contacts on your phone or computer in Calendar and contacts on the iPhone and iPad, Calendar and contacts on Android with DAVx5, Calendar and Contacts on the Mac and Calendar and contacts in Thunderbird. If they still don't come through despite the correct password, read Calendar or contacts don't show up on the phone.