The removal of the simple material room has been explained numerous times.  Simple Material Room only works on FireFly materials and only with the Poser Surface.  Make a hybrid material and it will fail.  But not in a way that a newbie is going to understand.  So, you could leave in something that is broken and will cause more and more problems or replace it with something that will actually work.  At some point people are going to have to use the material room so might as well start them off with the room that will work with both render systems.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13