Connecting to a Mac
This error means that the username and/or password you used to establish the Screen Sharing connection to a Mac are incorrect.
This could also mean that your are not using the proper Mac user credentials or that your Mac user isn't allowed to connect via the Remote Management service.
Please refer to these articles for more information:
Connecting to another computer type
On Linux, Raspberry Pi or Windows, this means that the VNC password is incorrect.
Refer to the initial computer configuration articles for more information: