ORA-29861 domain index is marked LOADINGFAILEDUNUSABLE

Exec dbms_network_acl_admin.create_acl ('utl_http_access.xml','Normal Access','DPCDSL',TRUE,'connect',NULL,NULL);
Exec dbms_network_acl_admin.add_privilege (acl => 'utl_http_access.xml', principal =>  'DPCDSL',is_grant => TRUE, privilege => 'resolve');
Exec dbms_network_acl_admin.assign_acl ('utl_http_access.xml', '*',NULL,NULL);
Commit ;


ERROR at line 1:
ORA-29861: domain index is marked LOADING/FAILED/UNUSABLE
ORA-06512: at "SYS.DBMS_NETWORK_ACL_ADMIN", line 252
ORA-06512: at line 1




select owner,index_name from all_indexes where domidx_status != 'VALID' or domidx_opstatus !='VALID';

alter index xdb.XDB$ACL_XIDX rebuild;