Unable to process Civil Cells

Hello,

I have place numerous civil cell in my corridor model. In order to make processing and editing them more manageable I turned off the active terrain and deactivated all rules in my model. Now that my active terrain is on and the rules are reactivated, the civil cells are not tying into the existing ground. I've tried to process the civil cell and it says "element not valid for tool." Any ideas as to why this is? I don't see why it would not process. I believe this was the correct way to place civil cells.

Thanks.