When you find that a password for a website or the wifi isn’t working, it’s possible that your Mac is retaining an older password. This is especially likely if your password has changed since the last time you used it on your Apple devices.
Macs use a feature called Keychains to store this information. While this is a useful feature, it can sometimes keep you out of an account if your password has changed.
You can delete outdated Keychain passwords. Here’s how:
1. Open the Keychain Access app from the Applications window on your Mac.
2. Find the Keychain you want to delete, and select it with a click.
3. From the File menu, choose Delete Keychain [keychain name].
4. Select Delete References.
The next time you visit the website or try to log onto the wifi, you will need to re-enter your username and your new password.