**Service** [CreativeService](https://developers.google.com/ad-manager/api/reference/v202605/CreativeService.RequiredSizeError.Reason) [CreativeSetService](https://developers.google.com/ad-manager/api/reference/v202605/CreativeSetService.RequiredSizeError.Reason) [ForecastService](https://developers.google.com/ad-manager/api/reference/v202605/ForecastService.RequiredSizeError.Reason) [LineItemCreativeAssociationService](https://developers.google.com/ad-manager/api/reference/v202605/LineItemCreativeAssociationService.RequiredSizeError.Reason) [LineItemService](https://developers.google.com/ad-manager/api/reference/v202605/LineItemService.RequiredSizeError.Reason) **LineItemTemplateService** [NativeStyleService](https://developers.google.com/ad-manager/api/reference/v202605/NativeStyleService.RequiredSizeError.Reason) [OrderService](https://developers.google.com/ad-manager/api/reference/v202605/OrderService.RequiredSizeError.Reason) [PublisherQueryLanguageService](https://developers.google.com/ad-manager/api/reference/v202605/PublisherQueryLanguageService.RequiredSizeError.Reason) **Dependencies** [RequiredSizeError](https://developers.google.com/ad-manager/api/reference/v202605/LineItemTemplateService.RequiredSizeError) ▼ **RequiredSizeError.Reason**

*** ** * ** ***

Namespace
:
    `https://www.google.com/apis/ads/publisher/v202605`

| Enumeration | Description |
|---|---|
| `REQUIRED` | [Creative.size](https://developers.google.com/ad-manager/api/reference/v202605/CreativeService.Creative#size) or [LineItem.creativePlaceholders](https://developers.google.com/ad-manager/api/reference/v202605/ForecastService.LineItem#creativePlaceholders) size is missing. |
| `NOT_ALLOWED` | [LineItemCreativeAssociation.sizes](https://developers.google.com/ad-manager/api/reference/v202605/LineItemCreativeAssociationService.LineItemCreativeAssociation#sizes) must be a subset of [LineItem.creativePlaceholders](https://developers.google.com/ad-manager/api/reference/v202605/ForecastService.LineItem#creativePlaceholders) sizes. |
| `UNKNOWN` | The value returned if the actual value is not exposed by the requested API version. |