I have Poser 11 installed. I had to install that DSON file when I got Poser 11. After I read this, I went to Poser 12 and tried to load M4 into Poser 12. He loaded fine. With no error. I also loaded his morphs++. And then I went and applied one of his textures. I did not install DSON into Poser 12. It didn't ask me to. If M4 needs it then it must have used the one from the Poser 11 install. Everything loaded quickly too.