[@robin-w Moderator 6 years, 8 months ago]

I don’t know how technical you are, this one does the opposite

function rew_min_length ($reply_content) {
	if (strlen($reply_content)<61) {
		bbp_add_error( 'bbp_reply_content', __( '<strong>ERROR</strong>: Your reply must be at least 60 characters.', 'bbpress' ) );
	}
return $reply_content ;
}

add_filter( 'bbp_new_reply_pre_content', 'rew_min_length' );