> [!CAUTION]
> **Caution:** This documentation is for Google Ads API **v24** . The latest active version is [**v26**](https://developers.google.com/google-ads/api/reference/rpc/latest/UserDataErrorEnum.UserDataError).

Enum describing possible request errors.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v24/errors/user_data_error.proto)

| Enums ||
|---|---|
| ## `OPERATIONS_FOR_CUSTOMER_MATCH_NOT_ALLOWED` | Customer is not allowed to perform operations related to Customer Match. |
| ## `TOO_MANY_USER_IDENTIFIERS` | Maximum number of user identifiers allowed for each request is 100 and for each operation is 20. |
| ## `UNKNOWN` | The received error code is not known in this version. |
| ## `UNSPECIFIED` | Enum unspecified. |
| ## `USER_LIST_NOT_APPLICABLE` | Current user list is not applicable for the given customer. |