If you manually add a new lock to your keychain you have to enter a lock pin in order to prove that you are the owner of the lock.
When you open the detail view of a previously added lock and tap on PERMISSIONS you probably have to sync your lock. This can happen when you have updated your app from a previous app version or when you entered a wrong lock pin before (see screenshot below):
In case the lock is already claimed by someone else, you won't be able to sync your lock and you will see an error message (Lock already claimed by another user).
What can I do?
Please login at www.my-lock.com (use your e-mail and password during registration of app) and add the lock manually in the lock overview screen.
Enter Lock ID, Lock Pin and a name and press ADD. You'll get a more detailed information about current ownership of the lock.