assert key created_at exist in config_states

modules/config_states.py

@@ -31,10 +31,11 @@ def list_config_states():
             try:
                 with open(path, "r", encoding="utf-8") as f:
                     j = json.load(f)
+                    assert "created_at" in j, '"created_at" does not exist'
                     j["filepath"] = path
                     config_states.append(j)
             except Exception as e:
-                print(f'[ERROR]{path}, {e}')
+                print(f'[ERROR]: Config states {path}, {e}')
 
     config_states = sorted(config_states, key=lambda cs: cs["created_at"], reverse=True)