Add datavars close after return ViewInfo

api/server/api_types.py

@@ -303,6 +303,7 @@ class ViewInfo(DataVarsSerializer):
                     self.groups.append(GroupField(dv=datavars,info=groupInfo,
                                          last=(lastGroup==i),expert=expert,
                                          brief=brief))
+            datavars.close()
         else:
             self.groups = groups