Some users need to uninstall and reinstall MetaMask because the app needs a refresh. As long as you kept your seed words safe, this is very easy! Just delete the extension, reinstall it, and import your twelve seed words. Then you'll set the password you want to use (this can be the same one you used before or a whole new password), and confirm your email address and username again on the CryptoKitties website.
What are seed words? Why are they important?
Your seed words are like a very, very important password. They let you restore your MetaMask account in the case it's deleted. If MetaMask is uninstalled from your computer, or if you need to use a different computer, you can use your seed words to reestablish access to your wallet. This also means that anyone with your seed words can access your account and steal your assets. Please be sure to save your seed words, and do not share them with others.
Why is MetaMask Locked?
Occasionally the 'My Profile' page displays a lock screen. This happens because MetaMask automatically locks your account after a certain period of time. To unlock, simply click on the MetaMask extension and type in your password.
What is a "wallet address"?
Your public wallet address (e.g. 0xaba935f589805095a892ecefdb6eb83eff45d67) is a unique identifier for your wallet. It's like a name. You can share it freely with others, and it's used to direct assets to your wallet.