Node error

query_engine = index.as_query_engine()
response = query_engine.query(query)

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
/tmp/ipykernel_113122/3918986344.py in <module>
      1 query_engine = index.as_query_engine()
----> 2 respons = query_engine.query(query)

. . . . .

~/.local/lib/python3.10/site-packages/llama_index/data_structs/node.py in __post_init__(self)
     64         # NOTE: for Node objects, the text field is required
     65         if self.text is None:
---> 66             raise ValueError("text field not set.")
     67 
     68         if self.node_info is None:

ValueError: text field not set.