Hi, glad to share the latest Oxygen OS of OnePlus X.
Release date: 2015/11/05
Make sure that your phone can boot and work normally. Then you download the firmware here.
Make sure that the battery capacity is above 30% and the available internal storage is above 2GB.
2. Upgrade steps
(1). Download the firmware package.
(2). Copy the zip. file named “OnePlusOxygen_14_OTA_003_all_201510241934″ to your OnePlus X.
(3). Power off, then press the “Volume -” and “Power” buttons together, release them after a vibartion to enter recovery mode.
(4). Choose language.
(5). Select “install from SDcard”
(6). Choose the ROM you need, click OK to start upgrading.
The phone will reboot to finish upgrade.