If your Xibo player starts and appears to be a minimised / off screen, please check the following
Display Settings -> Edit display profile assigned to your player -> Location tab
If you specified width to a specific value, but left height at 0, that will cause the problem described above.
Please ensure that both width and height are set:
To 0 - in which case player will take the screen size and cover whole screen
To specific values different than 0.
For multiple client installation, the second player must always have width, height and offset specified, please see the following manual page for more details - https://xibo.org.uk/manual/en/install_windows_client_multiple.html