examples/docqa/lance-rag-gh-issues.py errors on run

[Handfish]

ValueError: Vector column vector has NaNs. Set on_bad_vectors='drop' to remove them, or set on_bad_vectors='fill' and fill_value=<value> to replace them.

If I edit .venv/lib/python3.12/site-packages/langroid/vector_store/lancedb.py and include on_bad_vectors='drop' under both calls to create_table - I get the following error:

TypeError: bad operand type for unary ~: 'NoneType'