AI-generated Key Takeaways
- 
          
The content details the
CustomFieldValueError.Reasonenumeration, which provides reasons for target errors related to custom fields. - 
          
The enumeration lists specific reasons such as
CUSTOM_FIELD_NOT_FOUND,CUSTOM_FIELD_INACTIVE,CUSTOM_FIELD_OPTION_NOT_FOUND, andINVALID_ENTITY_TYPE. - 
          
The
UNKNOWNreason is returned when the actual error value is not exposed by the requested API version. 
The reasons for the target error.
- Namespace
 - 
               
https://www.google.com/apis/ads/publisher/v202508 
| Enumeration | Description | 
|---|---|
                        CUSTOM_FIELD_NOT_FOUND
                      | 
                     An attempt was made to modify or create a CustomFieldValue for a CustomField that does not exist. | 
                        CUSTOM_FIELD_INACTIVE
                      | 
                     An attempt was made to create a new value for a custom field that is inactive. | 
                        CUSTOM_FIELD_OPTION_NOT_FOUND
                      | 
                     An attempt was made to modify or create a CustomFieldValue corresponding to a CustomFieldOption that could not be found. | 
                        INVALID_ENTITY_TYPE
                      | 
                     An attempt was made to modify or create a CustomFieldValue with an association to an entity of the wrong type for its field. | 
                        UNKNOWN
                      | 
                     The value returned if the actual value is not exposed by the requested API version. |