Hello there,
Good day. Thank you for your question.
If the firmware version is 01.11.xx or the bootloader version is 01.09 or older and there might be issues with a direct update to 01.24.xx. To avoid this, you need to first update the device to firmware 01.26.01.rev99.
You will find all the firmware and manual in the link below (at the bottom right of the page) -
https://teltonika-gps.com/product/fm1100/
Kindly go through this and let me know if it helps.
Best regards.