It’s likely that there’s a mismatch between the Firmware version running on the FMA120 device and the Configurator Tool you are using.
I suggest that you contact your Teltonika Sales Manager to request the Configurator Tool that’s compatible with the Firmware version currently running on the FMA120.
If you don’t have any contacts with our Sale Managers, please contact with them on our official website https://teltonika-gps.com/ and click on the “Contact Us” button. When you will click, please fill the form and submit it.