Attached are two screen shots of ERC error messages and the associated schematic section. These errors all result in no physical connection being made in the board layout so I need to solve them and understand what's happening. The F1 Help apparently doesn't provide and answer to these specific messages.
"XXX overlaps pin". I have removed and remade this connection a half dozen times being careful to make sure the "wire" does not overlap the end of the "pin" but I keep getting them.
"Only INPUT pins on N$3". This is the input side of a 7805 VR being connected to the 5V output side of a barrel jack.
"Unconnected pin on U$1 NEG" but it certainly looks connected to me. I created the Library part and I have double checked that it has the Physical Pin "NEG" connected to the Logical Pin "POS".