Downloading OpenTX Companion
OpenTX Companion 2.1 is available for download at http://www.open-tx.org/downloads.html
This is major version with completely new telemetry handling. Please read this thread before upgrading from a previous version, and carefully check the changelogs on each upgrade. This branch is the first to support the FrSky Taranis X9E (tray version).
Updating firmware with Lua option selected
When updating the firmware on your transmitter, be sure the lua option is checked in the settings for your radio profile (Main menu -> Settings ->Settings...) as shown below.
Also note that the SD Structure path should contain a valid path to a copy of your transmitter's SD card contents.