Grayed out floor wont render

[cjp]

I do not know what I did, but for some reason my second floor is grayed out (see attached elevation image). It also wont render the grayed out portions. It is almost as if something was turned off. Does anyone know what happened and how to change it back to normal? Thanks in advance. 

[cjp]

Even the plan view is grayed out compared to the first level plan

[constantin.stroescu · Accepted solution]

it could be , because second Level is in another Phase that the others ...maybe it is in Existing and the others are New and the Phase Filter is Show Complete or Show Prevous +New.

Verify, also from Manage >Phases >Phasing > Overrides....

[cjp]

That was the problem. Thank you. Being fairly new to Revit, I did not know these phases existed and would like to be able to use them. Does Revit automatically put certain elements in these catagories based on what it is etc. I am currently doing the existing structure is there a way to put it all in existing at once (when I highlight the whole project it does not allow me to change the phase). Can certain objects be in multiple phases i.e. walls that stay throughout. I assume that I can put certain objects in different phases and they will show and dissapper as I specify. Thanks for the new knowledge.