Error message

• Warning: Cannot modify header information - headers already sent by (output started at /home/maddogt/public_html/includes/common.inc:2561) in drupal_send_headers() (line 1040 of /home/maddogt/public_html/includes/bootstrap.inc).
• PDOException: in field_sql_storage_field_storage_write() (line 425 of /home/maddogt/public_html/modules/field/modules/field_sql_storage/field_sql_storage.module).