// don't die on autoload

classes/Autoload.php

@@ -137,24 +137,18 @@ class Autoload
 
 		// Write classes index on disc to cache it
 		$filename = $this->root_dir.Autoload::INDEX_FILE;
-		if ((file_exists($filename) && !is_writable($filename)) || !is_writable(dirname($filename)))
-		{
-			header('HTTP/1.1 503 temporarily overloaded');
-			// Cannot use PrestaShopException in this context
-			die('/cache/class_index.php is not writable, please give write permissions (chmod 666) on this file.');
-		}
-		else
-		{
 		$filename_tmp = tempnam(dirname($filename), basename($filename.'.'));
-			if($filename_tmp !== FALSE and file_put_contents($filename_tmp, $content, LOCK_EX) !== FALSE)
+		if ($filename_tmp !== false && file_put_contents($filename_tmp, $content, LOCK_EX) !== false)
 		{
-				@rename($filename_tmp, $filename);
+			if (!rename($filename_tmp, $filename))
+				unlink($filename_tmp);
+			else
 				@chmod($filename, 0666);
 		}
-			else
 		// $filename_tmp couldn't be written. $filename should be there anyway (even if outdated), no need to die.
+		else
 			error_log('Cannot write temporary file '.$filename_tmp);
-		}
+
 		$this->index = $classes;
 	}