I am new to PCB designing and Started with Altium Designer for PCB Design. I have created the Schematic doc for Arduino Nano with all its components having their schematic and Footprints in the schematic library and PCB library. And I have also Net Labeled all the components in Schematic Doc. Now when I Go to PCB doc for Creating the doc for creating designing and placement of by components, I go to Design--> Import Changes from "filename "( when My PCB doc is opened) I get these windows
Now I am not able to understand these errors and how to solve them, why they are coming. So anybody can provide their valuable suggestions?