Solving common problems

Most problems with a password manager have a simple cause. Below are the most common ones, with the solution.

Your manager doesn't fill anything in

First check the address in the address bar. If your manager suddenly doesn't fill anything in on a site where it always worked, it could be a fake site. In that case, don't copy your password by hand. Type the address yourself or use your bookmark.
Is the correct address in the item? The manager only fills in if the website's address matches the item. If a service has moved to a new address, check this another way and add the new address.
Is your vault locked? Unlock it and try again.
Are your browser and your manager both filling in? Turn off password saving in your browser (see Installing Bitwarden in your browser, on your computer and on your phone).

KeePassXC must be open and your database unlocked. The extension's icon shows what's wrong.
In the extension, click Reconnect.
Under Tools, Settings, Browser Integration, check that your browser is ticked.
On Linux, browsers installed as Flatpak or Snap usually don't work with the extension (see KeePassXC in your browser, on your phone and on more computers).

Bitwarden: look in the app or extension for the button to sync your vault now. Check that you're logged in on both devices in the same region and with the same account.
KeePassXC: check that Nextcloud has synced the file. If there's a conflict file, merge it (see KeePassXC in your browser, on your phone and on more computers).

The clock on your computer or phone must be correct. Set the time to automatic.
Check that you're using the code for the right account, and that it hasn't just expired.
If it still doesn't work, use a backup code from that website and set up the code again (see Two-step verification codes (TOTP) in your manager).

Lost the phone with your authenticator app? Log in to Bitwarden with your master password and your recovery code (see Securing your Bitwarden account with two-step login).
Forgotten your master password? Read Forgotten your master password: what can you still do?.
Bitwarden says your account doesn't exist? Check the region: bitwarden.eu or bitwarden.com.

Can't get into My WebOké, DirectAdmin or Nextcloud, even with the correct password from your manager? Then take a look at Solving login problems, Can't log in: code, password or throttling or Setting, changing or forgetting your password. If your email program keeps asking for your password after you've changed it, it still has the old password: enter the new one, on your phone too.