diff --git a/mlrun/datastore/targets.py b/mlrun/datastore/targets.py
index 3a65318e53..f05ef8e894 100644
--- a/mlrun/datastore/targets.py
+++ b/mlrun/datastore/targets.py
@@ -274,7 +274,7 @@ def _get_store(self):
         return store
 
     def _get_column_list(self, features, timestamp_key, key_columns):
-        column_list = None
+        column_list = []
         if self.columns:
             return self.columns
         elif features:
diff --git a/mlrun/runtimes/serving.py b/mlrun/runtimes/serving.py
index 277c8a1140..3f8601a7b2 100644
--- a/mlrun/runtimes/serving.py
+++ b/mlrun/runtimes/serving.py
@@ -452,7 +452,7 @@ def _get_runtime_env(self):
             "function_uri": self._function_uri(),
             "version": "v2",
             "parameters": self.spec.parameters,
-            "graph": self.spec.graph.to_dict(),
+            "graph": self.spec.graph.to_dict() if self.spec.graph else {},
             "load_mode": self.spec.load_mode,
             "functions": function_name_uri_map,
             "graph_initializer": self.spec.graph_initializer,
diff --git a/mlrun/serving/states.py b/mlrun/serving/states.py
index fbd84fd55b..2ce4322c5b 100644
--- a/mlrun/serving/states.py
+++ b/mlrun/serving/states.py
@@ -774,11 +774,6 @@ def has_loop(state, previous):
         if self.on_error and self.on_error in start_states:
             start_states.remove(self.on_error)
 
-        if (
-            not start_states
-        ):  # for safety, not sure if its possible to get here (since its a loop)
-            raise GraphError("there are no starting states (ones without .after)")
-
         if (
             len(responders) > 1
         ):  # should not have multiple steps which respond to request