Already fixed for 2.1.2.
Open projectpost.php, find this:
PHP Code:
require_once(DIR . '/includes/functions_ptimporter.php');
$threadinfo = verify_id('thread', $threadid, 1, 1);
Replace with this:
PHP Code:
if (in_array($_REQUEST['do'], array('processimportthread', 'importthread', 'importthread2')))
{
require_once(DIR . '/includes/functions_ptimporter.php');
$threadinfo = verify_id('thread', $threadid, 1, 1);
}