don't assume response is a dict (it can be a bool)

facebook/__init__.py

@@ -139,7 +139,7 @@ def request(self, path, args=None, post_args=None):
             response = _parse_json(file.read())
         finally:
             file.close()
-        if response.get("error"):
+        if isinstance(response, dict) and response.get("error"):
             raise GraphAPIError(response["error"]["type"],
                                 response["error"]["message"])
         return response