A lot of old threads have smilies that point to:
This causes an unwanted user/password popup.
Example in a recently bumped thread:
The response that comes with it "I used to be an coder like you, then I took an arrow in the knee. "
Perhaps not easy to fix 
$results = get_rows(query('SELECT id, content FROM table_where_the_posts_are_at WHERE content LIKE "%https://files.renoise.com/forum/emoticons/%"'));
$mysql = '';
foreach ($results as $r)
{
$fixed = str_replace('https://files.renoise.com/forum/emoticons/', 'https://files.renoise.com/forum/emoticons/', $r['content']);
$mysql .= 'UPDATE table SET content = "' . escape($fixed) . '" WHERE id = ' . $r['id'] . ';';
}
query($mysql);
you know, something like that 