One, do not use the DIM.  Manually download and unzip the folders.  Make a new external runtime.

Install both the Genesis whatever version stater content and the Poser companion files to the same external runtime.

Make sure you move the runtime folder that is inside the content folder of the zip out of the content folder and place it as you would any other external Poser runtime.

If Poser can't locate the textures when you click on them in the material room then they aren't where Poser can find them.  Poser doesn't recognize or look inside the content folder.

Beyond that, it can be a hit or miss proposition.  If you have issues with the DSON, you will have to go to DAZ about them.  SMS will not give tech support for DAZ products.