Revit Face Based Ceiling Components in Ceiling hosted incorrectly

[jkhmiller]

I have inserted a diffuser on both a basic ceiling and a compound ceiling. The diffuser will host properly on the basic ceiling but not the compound. I know that sometimes face based families will not host properly depending on which direction a reference plane is drawn (left to right or right to left), but this is a ceiling, not a reference plane.

Should I be modeling the ceiling a certain way? Is it something with the family?

[RevitNinja]

I forget exactly what it is, but yes, there is a problem with the ceiling families (other than basic).