Can't find FULLTEXT index matching the column list [1191]Tema Solucionado

[uruguayito]

Hola después de tanto tiempo.
Hoy tratando de instalar este mod: http://www.phpbb-es.com/foro/similar-to ... 20527.html
(MUY sencillo por cierto), luego de ejecutar la consulta SQL que pide: ALTER TABLE phpbb_topics ADD FULLTEXT (topic_title);

todo bien, hasta que al ir al foro y tratar de leer cualquier tema, me salta este error:

Código: Seleccionar todo

Error General
SQL ERROR [ mysqli ]

Can't find FULLTEXT index matching the column list [1191]

SQL

SELECT f.forum_id, f.forum_name, t.topic_id, t.topic_title, u.user_id, u.username, u.user_colour, t.topic_replies FROM (phpbb_topics t) LEFT JOIN phpbb_users u ON (u.user_id = t.topic_poster) LEFT JOIN phpbb_forums f ON (f.forum_id = t.forum_id) WHERE MATCH (t.topic_title) AGAINST ('Estilo para dispositivos móviles' ) >= 0.5 AND t.topic_status <> 2 AND t.topic_id <> 11 GROUP BY t.topic_id ORDER BY t.topic_last_post_time DESC LIMIT 5

BACKTRACE

FILE: (not given by php)
LINE: (not given by php)
CALL: msg_handler()

FILE: [ROOT]/includes/db/dbal.php
LINE: 757
CALL: trigger_error()

FILE: [ROOT]/includes/db/mysqli.php
LINE: 189
CALL: dbal->sql_error()

FILE: [ROOT]/includes/db/mysqli.php
LINE: 231
CALL: dbal_mysqli->sql_query()

FILE: [ROOT]/includes/db/dbal.php
LINE: 170
CALL: dbal_mysqli->_sql_query_limit()

FILE: [ROOT]/viewtopic.php
LINE: 1889
CALL: dbal->sql_query_limit()

¿cómo lo soluciono?