Only allow python refreshing if the file exists

korman/nodes/node_python.py

@@ -149,6 +149,7 @@ class PlasmaPythonFileNode(PlasmaNodeBase, bpy.types.Node):
         row = layout.row(align=True)
         if self.filename:
             row.prop(self, "filename")
+            if os.path.isfile(self.filepath):
                 operator = row.operator("node.plasma_attributes_to_node", icon="FILE_REFRESH", text="")
                 operator.python_path = self.filepath
                 operator.node_path = self.node_path