Ticket MAGETWO-57413
diff -Naur a/app/autoload.php b/app/autoload.php
--- a/app/autoload.php
+++ b/app/autoload.php
@@ -13,16 +13,7 @@ use Magento\Framework\Autoload\ClassLoaderWrapper;
  */
 define('BP', dirname(__DIR__));

-define('VENDOR_PATH', BP . '/app/etc/vendor_path.php');
-
-if (!file_exists(VENDOR_PATH)) {
-    throw new \Exception(
-        'We can\'t read some files that are required to run the Magento application. '
-         . 'This usually means file permissions are set incorrectly.'
-    );
-}
-
-$vendorDir = require VENDOR_PATH;
+$vendorDir = './vendor';
 $vendorAutoload = BP . "/{$vendorDir}/autoload.php";

 /* 'composer install' validation */

diff -Naur a/vendor/magento/framework/App/Arguments/FileResolver/Primary.php b/vendor/magento/framework/App/Arguments/FileResolver/Primary.php
--- a/vendor/magento/framework/App/Arguments/FileResolver/Primary.php
+++ b/vendor/magento/framework/App/Arguments/FileResolver/Primary.php
@@ -29,7 +29,7 @@ class Primary implements \Magento\Framework\Config\FileResolverInterface
         \Magento\Framework\Filesystem $filesystem,
         \Magento\Framework\Config\FileIteratorFactory $iteratorFactory
     ) {
-        $this->configDirectory = $filesystem->getDirectoryRead(DirectoryList::CONFIG);
+        $this->configDirectory = $filesystem->getDirectoryRead(DirectoryList::APP);
         $this->iteratorFactory = $iteratorFactory;
     }