Downloading large files with getFile on a self-hosted telegram-bot-api server hung for ~1 minute, then returned: {"ok":false,"errorcode":400,"description":"Bad Request: wrong fileid or the file is temporarily unavailable"}. Retrying several times eventually worked. Server logs showed FloodWait-style 429s from the media DC (Session closed: MTProto error: -429, Too Many Requests: retry after 8) during the download, so the file was genuinely unavailable at that moment.