How to make a board single-sided ?? In the tutorial I read:
"We wish to make a single-sided board for this simple circuit, so we'll tell the auto-router to use only one side. Right-click in an empty area and select "Global Autoroute>Select layer pair". In the dialog, select "Copper" for both Top Layer and Bottom Layer, and click OK. (Some people call it the "solder side" instead of the "copper side".) " BUT if I try, I get the message "The Top Layer and Bottom Layer must differ" why, please ?? (mode: track and autorouting was selected) thanks
