Database upload error

I’m moving from localhost to a live site and have this error when I try to upload the database:

CREATE TABLE wp_sfposts (

post_id BIGINT( 20 ) NOT NULL AUTO_INCREMENT ,
post_content LONGTEXT,
post_date DATETIME NOT NULL ,
topic_id BIGINT( 20 ) NOT NULL ,
user_id BIGINT( 20 ) ,
forum_id BIGINT( 20 ) NOT NULL ,
guest_name VARCHAR( 20 ) ,
guest_email VARCHAR( 50 ) ,
post_status INT( 4 ) NOT NULL DEFAULT ‘0’,
post_pinned SMALLINT( 1 ) NOT NULL DEFAULT ‘0’,
post_index MEDIUMINT( 8 ) DEFAULT ‘0’,
post_edit MEDIUMTEXT,
poster_ip VARCHAR( 39 ) NOT NULL DEFAULT ‘0.0.0.0’,
comment_id BIGINT( 20 ) ,
source SMALLINT( 1 ) NOT NULL DEFAULT ‘0’,
PRIMARY KEY ( post_id ) ,
KEY topicp_idx ( topic_id ) ,
KEY forump_idx ( forum_id ) ,
KEY user_idx ( user_id ) ,
KEY guest_name_idx ( guest_name ) ,
KEY comment_idx ( comment_id ) ,
KEY post_date_idx ( post_date ) ,
KEY post_content ( post_content )
) ENGINE = MYISAM DEFAULT CHARSET = utf8 AUTO_INCREMENT =2;

MySQL said: Documentation
#1170 – BLOB/TEXT column ‘post_content’ used in key specification without a key length

There is a post which mentions this error but the fix isn’t clear enough for me! I of course googled the error too and am looking at the database, but it was working fine not long ago on the localhost. Getting desperate now, can someone help please? Thanks.