Specific audience extension error reasons.
|Frequency caps are not supported by audience extension line items
|Audience extension line items can only target geography
|Audience extension line items can only target audience extension inventory units
|Audience extension line items do not support CreativeRotationType.SEQUENTIAL.
|The given ID of the external entity is not valid
|Audience extension line items only support LineItemType.STANDARD.
|Audience extension max bid is invalid when it is greater then the max budget.
|Bulk update for audience extension line items is not allowed.
|An unexpected error occurred.
|The value entered for the maximum daily budget on an audience extension line item exceeds the maximum allowed.
|Creating a campaign for a line item that already has an associated campaign is not allowed.
|Audience extension was specified on a line item but the feature was not enabled.
|Audience extension was specified on a line item but no audience extension account has been linked.
|Assocation creative size overrides are not allowed with audience extension.
|Some association overrides are not allowed with audience extension.
|Only one creative placeholder is allowed for an audience extension line item.
|Only one audience extension line item can be associated with a given order.
|Audience extension line items must be copied separately from their associated creatives.
|Audience extension is no longer supported and cannot be used.
|The value returned if the actual value is not exposed by the requested API version.