Don't worry about the darkended texture in the hip area - this happens by default if you load the original M4 in Poser (looks normal in DAZ Studio). If you use other MATs this will not happen. And if you use EZ's EZSkin2 it will vanish anyway.

Concerning your "Eryk" morph: did you install the 'Base M4' morphs and the 'Morphs ++ M4'? They are needed for other "commercial character morph packages" as "Eryk".

Since V4 works fine you will be able to install M4 too.