Last minute error

Traceback (most recent call last):
  File "./pricing_curve/Simulation.py", line 775, in calculate_pro_forma
    price_per_reservable_df, gate, region, market, currency, rate)
  File "./pricing_curve/Simulation.py", line 723, in collect_input_otf
    price_per_reservable, total_capacity_sum, market, currency, rate),
  File "./pricing_curve/Simulation.py", line 492, in _get_bases_sales_otf
    raise e
  File "./pricing_curve/Simulation.py", line 443, in _get_bases_sales_otf
    'initial_base_sales': self._get_bases_sales(location_name),
  File "./pricing_curve/Simulation.py", line 333, in _get_bases_sales
    raise e
  File "./pricing_curve/Simulation.py", line 330, in _get_bases_sales
    return float(row.base_sales)
AttributeError: 'NoneType' object has no attribute 'base_sales'