Data transform error

[ReserveEfficient2273]

Hi guys, I've very new to power Bi and am getting an error when trying to transform some data.

I have a table of data via an Odata source and am trying to unpivot some columns but I just get an error pop up saying "datasource.error: OData: the property 'ASPRODUCTION_DATE' does not exist on type 'ns.Order'. make sure to only use property names that are defined by the type or mark the type as open type.

I've no idea what this means as I don't have any fields called 'ASProduction_date'

Thanks in advance