When this message appears, it means that the machine is already registered with a serial number that is linked to an account.
The two most common situations where this occurs are:
1. You have logged in using a different method than the one you originally used to connect to the machine. For example, if you logged in with Facebook or email and connected to the robot, but the next time you open the app, you log in with Apple ID, Gmail, etc. You cannot see the machine on the list and try to connect again, but it is already linked to the original login method. So log in with the login method you used the last time you controlled the device.
2. When purchasing a used machine, and the previous owner has not deleted the machine from the app's device list. In that case, you should contact the previous owner and ask them to delete the machine from the app.
If the above does not resolve the issue, please send a copy of the proof of purchase along with a picture of the shield on the robot with the visible serial number, and our service will ensure a solution.