Wow, I should have thought about that a little more. I placed the PopUpRendererSkin into the 'Query' folder and that removed the error. However, there is still an element from the other custom skin showing in the popup. What I am trying to do is actually use the default PopUpRendererSkin for the Query widget (with just a few minor changes - ie, remove the media box border and make the popup larger). Here is the code from the default.css which may be affecting the Query Widget in some way...esri|PopUpRenderer
{
skinClass: ClassReference("agrg.skins.CustomPopup");
}
eSearch|SearchWidget esri|PopUpRenderer {
skinClass: ClassReference("com.esri.ags.skins.PopUpRendererSkin");
}
and I noticed this code inside the CustomPopup.mxml: [HostComponent("com.esri.ags.webmap.PopUpRenderer")]