I just had 2 sets of boards manufactured that are completely useless because of a this. If you add traces but do not force a ground plane update manually before exporting, then the plane will not give clearance for the new track, and will just short out. There isnt even a DRC warning that there is a short between the line and ground. So if you had just run a powerline to a component, you end up with a dead-short to ground, and no warnings / errors when doing the DRC check. To Reproduce Have a circuit laid out except one track. Save and rebuild your ground plane Add the last track Click export gerber If you save and come back to the PCB, it gets rebuilt when you log in, This affects when you add a track just before you export. For those wondering, I only noticed this after burning out components and causing quite a bit of smoke.