Starting July 14, 2025 , Google Ads scripts will begin to throw errors for requests related to ad customizers for expanded text ads  and feed-based legacy ad extensions. 
Ad customizer changes 
Any requests related to Ad Customizer  entities, such as AdsApp.AdCustomizerSource  or AdsApp.newAdCustomizerSourceBuilder , will begin to return sunset errors. These entities have been read-only since deprecation in 2022  and haven’t been served on any ads since May 2024 . They were also fully removed from the Google Ads API in the v19 release .
Ad extension changes 
Feed-based Ad Extensions  were sunset in 2022  in favor of asset-based extensions. Users were asked to migrate, or were migrated automatically, but were able to access legacy functionality through the withOnlyLegacy() methods on various selectors. The withOnlyUpgraded() method was added to allow users to only use upgraded asset-based extensions. Starting July 14, 2025 , the legacy functionality will be removed, and withOnlyLegacy() methods will begin to throw a sunset error. The withOnlyUpgraded() methods will log a warning, since it will no longer be necessary to specify the use of asset-based extensions when they are the only option.
If you have any questions, ask them in the Google Ads scripts forum . We're here to help!