This error means one of two things:
The username or password used to establish the secure connection is incorrect or not allowed
For connections to Windows, Linux or Raspberry pi, make sure that you use the correct username/password that was configured with your SSH server.
No SSH server is running on the remote computer
In order to use a secure connection (SSH), the remote computer needs to be configured to receive encrypted connections. You can refer to this article for more information on how to allow a user to connect via a secure network connection.