ok..I have an error message "cannot implicitly convert (const float3) to float4"...and it points to that part of the code
Code:

---

...

float3 lighting = float3(0, 0, 0);
for (i = 0; i < 8; i ++) {
lighting += ppLightCalc(FinalColor, In.WPos, In.WNormal, i);

...
}
		
FinalColor += lighting;  

---

any hints?