diff --git a/server/website/website/db/base/parser.py b/server/website/website/db/base/parser.py
index 3b8ca9d..cf1daba 100644
--- a/server/website/website/db/base/parser.py
+++ b/server/website/website/db/base/parser.py
@@ -187,10 +187,7 @@ class BaseParser:
         return value in self.valid_true_val or value in self.valid_false_val
 
     def convert_dbms_metrics(self, metrics, observation_time, target_objective):
-        metric_data = {}
-        # Same as metric_data except COUNTER metrics are not divided by the time
-        # Note: metric_data is also not divided by the time now so base_metric_data is redundant
-        base_metric_data = {}
+        numeric_metric_data = {}
         numeric_metric_catalog = MetricCatalog.objects.filter(
             dbms__id=self.dbms_id, metric_type__in=MetricType.numeric())
 
@@ -210,12 +207,10 @@ class BaseParser:
 
             if metadata.metric_type == MetricType.COUNTER:
                 assert isinstance(converted, float)
-                base_metric_data[name] = converted
-                metric_data[name] = converted
+                numeric_metric_data[name] = converted
             elif metadata.metric_type == MetricType.STATISTICS:
                 assert isinstance(converted, float)
-                base_metric_data[name] = converted
-                metric_data[name] = converted
+                numeric_metric_data[name] = converted
             else:
                 raise ValueError(
                     'Unknown metric type for {}: {}'.format(name, metadata.metric_type))
@@ -227,10 +222,11 @@ class BaseParser:
                     target_objective, ', '.join(target_list.keys())))
 
         for target_name, target_instance in target_list.items():
-            metric_data[target_name] = target_instance.compute(
-                base_metric_data, observation_time)
+            # wait_class is needed to calculate target_objectives, but it is not numeric
+            numeric_metric_data[target_name] = target_instance.compute(
+                metrics, observation_time)
 
-        return metric_data
+        return numeric_metric_data
 
     def extract_valid_variables(self, variables, catalog, default_value=None):
         valid_variables = {}
diff --git a/server/website/website/views.py b/server/website/website/views.py
index 7bb437b..8740f5f 100644
--- a/server/website/website/views.py
+++ b/server/website/website/views.py
@@ -530,27 +530,29 @@ def handle_result_files(session, files, execution_times=None):
 
         worst_result = Result.objects.filter(metric_data=worst_metric).first()
         last_result = Result.objects.filter(session=session).order_by("-id").first()
-        last_conf = JSONUtil.loads(last_result.next_configuration)
-        last_conf = last_conf["recommendation"]
-        last_conf = parser.convert_dbms_knobs(last_result.dbms.pk, last_conf)
 
         # Copy worst data and modify
         knob_data = worst_result.knob_data
         knob_data.pk = None
-        all_knobs = JSONUtil.loads(knob_data.knobs)
-        for knob in all_knobs.keys():
-            for tunable_knob in last_conf.keys():
-                if tunable_knob in knob:
-                    all_knobs[knob] = last_conf[tunable_knob]
-        knob_data.knobs = JSONUtil.dumps(all_knobs)
+        if last_result.next_configuration is not None:
+            last_conf = JSONUtil.loads(last_result.next_configuration)
+            if last_conf.get("recommendation", None) is not None:
+                last_conf = last_conf["recommendation"]
+                last_conf = parser.convert_dbms_knobs(last_result.dbms.pk, last_conf)
+                all_knobs = JSONUtil.loads(knob_data.knobs)
+                for knob in all_knobs.keys():
+                    for tunable_knob in last_conf.keys():
+                        if tunable_knob in knob:
+                            all_knobs[knob] = last_conf[tunable_knob]
+                knob_data.knobs = JSONUtil.dumps(all_knobs)
 
-        data_knobs = JSONUtil.loads(knob_data.data)
-        for knob in data_knobs.keys():
-            for tunable_knob in last_conf.keys():
-                if tunable_knob in knob:
-                    data_knobs[knob] = last_conf[tunable_knob]
+                data_knobs = JSONUtil.loads(knob_data.data)
+                for knob in data_knobs.keys():
+                    for tunable_knob in last_conf.keys():
+                        if tunable_knob in knob:
+                            data_knobs[knob] = last_conf[tunable_knob]
+                knob_data.data = JSONUtil.dumps(data_knobs)
 
-        knob_data.data = JSONUtil.dumps(data_knobs)
         knob_name_parts = last_result.knob_data.name.split('*')[0].split('#')
         knob_name_parts[-1] = str(int(knob_name_parts[-1]) + 1) + '*'
         knob_data.name = '#'.join(knob_name_parts)