I have routeros 4.17, can upgrade bootloader from 2.29 to 2.

I have routeros 4.17 and I cant upgrade bootloader manualy from 2.29 to 2.39.
I downloaded file: ar7100-2.39.fwf from routerboard.com.
It restarts board but didnt upgrade.
Thanks

what’s in Log after reboot?..