For advanced users, you can flash firmware directly from the device's bootloader using an SD card.
This is the standard method provided by HTC. It is safe and does not void your warranty. Connect to a stable . Go to Settings on your HTC One X9. Scroll down and tap on About . Select Software Updates . Tap Check Now . Firmware Change Update on HTC One X9
Try a different USB port (preferably USB 2.0) or reinstall the HTC drivers. For advanced users, you can flash firmware directly
Before attempting any firmware modification, ensure your device is prepared to prevent data loss or hardware failure. For advanced users