I do had the same issue, As a quick solution i used the fb_strip_and_format_desc() function to trim the html characters.
https://www.facebook.com/keralathanima
Edit fb-social-publisher.php file goto line 232, use fb_strip_and_format_desc() in both name and caption array values like below
$args = array('access_token' => $fan_page_info[0][3],
'from' => $fan_page_info[0][2],
'link' => apply_filters( 'rel_canonical', get_permalink()),
'picture' => $post_thumbnail_url,
'name' => fb_strip_and_format_desc(get_the_title()),
'caption' => fb_strip_and_format_desc(apply_filters( 'the_excerpt', get_the_excerpt() )),
'description' => fb_strip_and_format_desc( $post ),
'message' => $fan_page_message,
);
Hope this will help to fix the issue.Thanks