What does the message: “Error on the robot. You have disconnected the desktop session … RPA needs keyboard, mouse and screen …” mean?

This message is informing that the Windows session where the process is running has left other applications without screen, keyboard and mouse resources, some of which the robot uses in its process.
For example: Outlook, browser, etc.
It is essential not to remotely enter the machine where the process is running using “Remote Desktop” while the robot is executing the tasks.
If they do this and then minimize the window or leave the connection, Windows disables the functions of keyboard, mouse, screen and many more.
So the programs that have been robotized stop responding.
If you don’t have the Terminal Server Control module of the RPA Suite, we recommend using “AnyDesk” or some other remote access tool in “console” mode to avoid this.