If an error has occurred or your system has an obstruction causing the Semi-Closed Loop System to trigger, it will activate the E-Stop mode on the machine. When this happens the first thing you need to do is take note of the line number that you are at in the G-Code window on the lower left part of the UCCNC screen. Write it down or take a photo with your cell phone.
To reset this, you press the Red reset button on the UCCNC screen and then press HOME ALL. This will reset each axis so that everything is back in sync with UCCNC. From that point, you can use the START FROM HERE button and restart the job from right where you left off.
You can view this video on how to use the START FROM HERE button: