Error ingesting futures data for Zipline

I'm receiving the following error when ingesting daily futures data into a Zipline bundle:

quantrocket_zipline_1|  winsorise_uint32(raw_data, invalid_data_behavior, 'volume', *OHLC)
quantrocket_zipline_1|/opt/conda/lib/python3.6/site-packages/zipline/data/bcolz_daily_bars.py:367: UserWarning: Ignoring 475 values because they are out of bounds for uint32: 

Please advise.

David