Media On Core Cloud: In the Ad Placement side panel, Attribute tab fails to save with SalesforceRuntimeException or ENTITY_IS_LOCKED Exception

Cause 1: Ad Availability View Configuration Media Type doesn't match Product Family

1.  Open the affected product. Navigate to App Launcher > Product Catalog Management > Products > [Product Name].
2.  Note the value in the Product Family [Family] field on Product [Product2].
3.  Navigate to App Launcher > Ad Availability View Configurations.
4.  Open the Ad Availability View Configuration [AdAvailabilityViewConfig] record used for the Side Panel Tabs Metadata (Configuration Type = Screen, Sub Type = sidePanel).
5.  Set the Media Type [MediaType] field to the same value as the product's Product Family. If the product family value (for example Retail or Digital) is not present in the Media Type picklist, navigate to Setup > Object Manager > Ad Availability View Configuration > Fields & Relationships > Media Type and add the value as a picklist value.
6.  If multiple product families exist, create one Ad Availability View Configuration [AdAvailabilityViewConfig] record per product family with the matching Media Type.
7.  Save the record.

Cause 2: Product Classification attribute is missing an Attribute Category

1.  Navigate to App Launcher > Product Catalog Management > Product Classifications > [Classification Name].
2. Open each attribute assigned to the classification.
3.  Set the Attribute Category [AttributeCategory] field to a valid category (for example General). Don't leave it blank, even if the attribute is linked to a category in the UI.
4.  Save each attribute.
5. Reassign the Product Classification to the affected Product [Product2] record if the classification was changed.

Cause 3: Record locked by an in-progress approval or pending DML

1.  Navigate to Setup > Approval Processes and confirm no active approval process is locking the Quote [Quote] record. The ENTITY_IS_LOCKED error can appear even when no approval work item is visible if a triggered flow holds a lock.
2.  Navigate to the Quote record and open Related > Approval History to confirm no pending approval items.
3.  If a record-triggered flow on Ad Quote [AdQuote] or Ad Quote Line Item [AdQuoteLineItem] performs DML on the parent Quote, set the flow to run after save and remove any synchronous update to the same Quote record being edited from the side panel.