Hello,
Thank you for your query.
You can use firmware version shown below on your FMB120 device.
From Firmware: FMB.Ver.03.25.14.Rev.03
From Configurator version: Teltonika.Configurator_1.4.10_B.3.25_C.101
FMB firmware errata can be found there: https://wiki.teltonika.lt/view/FMB_firmware_errata
To get latest firmware and configurator version please contact your sales manager.
Best Regards,
Teltonika Support.