diff --git a/agent/canvas.py b/agent/canvas.py
index 9919fe1da..f78167532 100644
--- a/agent/canvas.py
+++ b/agent/canvas.py
@@ -262,7 +262,7 @@ class Canvas(ABC):
         convs = []
         for role, obj in self.history[(window_size + 1) * -1:]:
             convs.append({"role": role, "content": (obj if role == "user" else
-                                                    '\n'.join(pd.DataFrame(obj)['content']))})
+                    '\n'.join([str(s) for s in pd.DataFrame(obj)['content']]))})
         return convs
 
     def add_user_input(self, question):
diff --git a/rag/nlp/query.py b/rag/nlp/query.py
index 2bc482b95..c58c99c4c 100644
--- a/rag/nlp/query.py
+++ b/rag/nlp/query.py
@@ -186,8 +186,5 @@ class EsQueryer:
                 s += v  # * dtwt[k]
         q = 1e-9
         for k, v in qtwt.items():
-            q += v  # * v
-        #d = 1e-9
-        # for k, v in dtwt.items():
-        #    d += v * v
-        return s / q / max(1, math.sqrt(math.log10(max(len(qtwt.keys()), len(dtwt.keys())))))# math.sqrt(q) / math.sqrt(d)
+            q += v
+        return s / q