I have this random blue line going through my PCB layout. It doesnt seem to be connected to anything. Is this telling me something useful or is this a bug? I tried restarting KiCad. It won’t go away.
Make sure “All Items” is on in the selection filter in the lower right corner.
Draw a box around it to select it.
Look at what it’s properties are (Either with e, or with PCB Editor / View / Show Properties Manager
A simpler way to select it would be to skip the first two steps, and then draw a small box from right to left over a part of that line, or to do a long mouse button press (which brings up a selection menu).
If all those things fail, then upload the PCB file (you can delete most of the project).
The color is right for a ratsnest line, but ratsnest lines start and end on pads or track segments. Do you have hidden items or hidden / disabled layers?
You can toggle ratsnest lines on/off, or between straight / curved to check whether it may be a ratsnest line.
I tried all of paulvdh suggestions and in the process I figured out that the blue line is indicating that two fill zones of the same name are not electrically connected. In my screenshot I had the fill zones turned off so maybe it wasnt clear what was going on. Thanks paulvhd for the suggestions.
