If you are encountering this error, the printer has encountered a movement in the G-Code which is not allowed. To prevent damage to the printer, the error has shown up.
To prevent damage to the electronics, this is a critical error and requires a system reboot. Please reslice your print job in Ultimaker Cura.
If this error persists, please raise a support ticket above. Please explain what you are encountering, how the error came about, and if you are using default print profile settings.