Old Adtran 904 2ndGen had T900G2A-A4-08-00-E.biz firmware, which I was able to upgrade to T900G2A-A4-09-00-E.biz. I am not able to upgrade to anything higher that is available, so I tried using T900G2A-R10-9-5-E.biz, which failed (see below). How can I get this unit upgraded? Eventually want to upgrade to the latest, R13.5.2
Verifying images. Please wait...
Unknown header version, ignoring...
Bad file signature.
'T900G2A-R10-9-5-E.biz' is not a valid image.
Primary image error. Primary boot configuration not updated!!!
Reverting to primary image "T900G2A-A4-09-00-E.biz"
Primary image: T900G2A-A4-09-00-E.biz
Backup image: T900G2A-A4-09-00-E.biz
The boot ROM that is on this unit is the same as on other 9XX units that we have and they have newer firmware on them.
Hardware version A
Boot ROM version 14.04.00
