This error is saying that r2 needs to have a "swizzle" on it that grabs only part of it.
Code:
mov r2.w,r8
I'm not sure what it's supposed to be, try using x, y, and z in place of W if the shader doesn't operate properly

. I'd have to look at the rest of the code to figure it out and ASM makes me dizzy

(I made Phoenix 2 for TI-89... all 68k asm.... YUCK!

)
-Rhuarc