I added a polygon fill. However it doesnt fill the entore board. Why is this?
try adding some GND vias, or normal GND-net tracks into the area that you want filled.
(there’s a useful via-stiching pro-tip on this forum)
I tried it. It just shows me that trace. It doesnt fill ground in that area.
You must add a ground connection. It cannot be a float (unconnected) ground via. So there must be a GND path and not a single end GND line… otherwise KiCad will optimize it and clear the “floating track”
Ah, okay, got it. Thanks