Currently I'm building an iOS app using tdlib, the first problem was, when user minimizes the app sockets are closed down, so td::Client crashes. Now I destruct client object every time when app goes background and recreate when it goes foreground.
And now there's another problem, previously saved file_ids are no longer available for download. Every downloadFile request fails with "400 - Invalid file id".
How do one save file ids for later download?