Default help please lost back up

hi,
i'm stuck with updating my nook hd+ to kitkat.
i seem to have lost the backup rom (i think i formatted the micro-sd that it was on by mistake).
i do not seem to be able to update to any rom as i get an error saying...
E: Can't open / external_sd/cm-11-20140606-nightly-ovation (1).zip
(bad)
installation aborted
it says this with all the roms i tried.
i did get the same problem with my S3 until i found the fusion rom, which worked ok.

ps i am on recovery v6.0.4.5

thanks in advance.