I'm really new to PCB layout and after creating my PCB layout and ordering it from PCB Way my audit was failed for reason "no top solder mask layer." What does that mean and how would I add that? If it helps here are my schematic and board design. Also in my zip file I had the .cmp file, .drd file, .dri file, .drl file, .gpi file, .plc file, .sol file, and .stc file.
Any help would be greatly appreciated, thanks.