I am very green with dynamo, so forgive me if this is a dumb question. I downloaded a .dyn that has this custom node. I am getting “Error: Custom node definition is not loaded!” when I try to Run it. How can I get this node? Is it part of a package?
What is the name of it? You need to find the dyf file with the same name. You could then put this side-by-side with the dyn, if you don’t have the package installed.
Dynamo Nodes 
I am very green with dynamo, so forgive me if this is a dumb question. I downloaded a .dyn that has this custom node. I am getting “Error: Custom node definition is not loaded!” when I try to Run it. How can I get this node? Is it part of a package?
What is the name of it? You need to find the dyf file with the same name. You could then put this side-by-side with the dyn, if you don’t have the package installed.
This node stopped working with floorplanview element in Revit 2019