Trouble installing openwrt on RE450v1

hello good day.

i got myself a re450 hardware version 1.

i already own 2 re450 hardware rev 2. and i installed open wrt on those with ease by selecting the firmware in the web gui.

the problem with v1 is i get a checksum error.

the v1 is still on firmware 1.0.0 from tp link

any other options that doesnt include serial? i dont have serial sadly.