When this error occurs, there was a problem between the communication of the motherboard, and the motion controller of the printer.
This error can occur if the printer has been idle in an unexpected state for too long.
Note: The Ultimaker 2+ Connect may boot up with stepping stone firmware, which prompts you to update. If the printer remains on the update screen for a longer period of time, the ER207 may be triggered. Please reboot the printer and update the firmware via USB.
Unfortunately this error most likely means there is a faulty component in the board. If you are encountering this error, please raise a support ticket above.