I'm getting this exception for a few users in their Fit files: FitParseError("No such dev_data_index=%s found" % (dev_data_index)) Looks like it's related to Battery Level and the dev_data_index is 0. <DataMessage: field_description (#206) -- local mesg: #3, fields: [field_name: Battery level, units: %, fit_base_unit_id: None, native_mesg_num: record, developer_data_index: 0, field_definition_number: 0, fit_base_type_id: float32, scale: None, offset: None, native_field_num: None]> Thanks in advance for any suggestions.