ok, I believe it might be better to completely remove the moderators block..
/******************************************************************************/
--- Converting moderators...
/******************************************************************************/
TRUNCATE {$to_prefix}moderators;
---* {$to_prefix}moderators
---{
$ignore = true;
if (empty($row['id_member']))
unset($row);
---}
SELECT member_id AS id_member, forum_id AS id_board
FROM {$from_prefix}moderators
WHERE member_id != -1;
---*
After removing this code the converter should finish without errors.
I'd be interested in the result of this query:
SELECT member_id AS id_member, forum_id AS id_board
FROM ipb_moderators
WHERE member_id != -1;
maybe you can execute it via phpMyAdmin and post the result.