Migrate d2d picture migration destination path incorrect
You may try to specify the destination_dir in the __construct() instead of passing the arguments e.g.

class FooUserPictureMigration extends DrupalPicture6Migration {

  public function __construct(array $args) {
    parent::__construct($args);

    // Add simple field mappings
    $this-&gt;addFieldMapping('source_dir', FALSE)
         -&gt;defaultValue(MIGRATE_D6_USERPIC_SRC_DIR);
     $this-&gt;addFieldMapping('destination_dir', FALSE)
         -&gt;defaultValue(MIGRATE_D6_USERPIC_DST_DIR);


Where MIGRATE_D6_USERPIC_SRC_DIR is your source dir and MIGRATE_D6_USERPIC_DST_DIR is your destination dir (e.g. public://pictures).



Alternatively you can fix the user avatars by the following one-time query:

UPDATE users u
SET picture = (SELECT fid FROM file_managed fm WHERE filename = (SELECT SUBSTRING_INDEX(picture, '/', -1) as filename FROM DRUPAL6_DB.users as d6u WHERE name = u.name AND picture &lt;&gt; '' AND fm.filename = SUBSTRING_INDEX(picture, '/', -1)))
  WHERE u.name &lt;&gt; '' 
    AND u.name IN (SELECT name FROM DRUPAL6_DB.users WHERE picture &lt;&gt; '')


WHERE DRUPAL6_DB is your database name for Drupal 6.