4-bit binary multiplier circuit
You scrambled the order of the input connections on your 4-bit adder. On the submodule, you have

A3 B3 A2 B2 A1 B1 A0 B0


but in your main circuit, you have them wired up as if they were

A3 A2 A1 A0 B3 B2 B1 B0


... Unless there's some magic that I can't see in your diagrams.