node_wrangler/operators.py

@@ -1103,6 +1103,17 @@ class NWMergeNodes(Operator, NWBase):
         if selected_mix and selected_math and merge_type == 'AUTO':
             selected_mix += selected_math
             selected_math = []
+
+        # If no nodes are selected, do nothing and pass through.
+        if not any(nodes_list for nodes_list in [selected_mix,
+                                                 selected_shader,
+                                                 selected_geometry,
+                                                 selected_math,
+                                                 selected_vector,
+                                                 selected_z,
+                                                 selected_alphaover]):
+            return {'PASS_THROUGH'}
+
         for nodes_list in [
                 selected_mix,
                 selected_shader,