Hey,
If you try to drag a Xform into the action graph from the stage tab and set to read it throws a “name is empty” error. Even once attribute name is selected its still the same.
You can currently bypass this by selecting read prim in the nodes tab as a work around.
This also is not quite right as once you have selected attribute the value is still unresolved even when the output attribute value is functioning as a double3 for example.
Cheers