Help needed with upgrading firmware

Hi
I've downloaded and unpacked xfvdw-sl-16-0-nwsp2-30dec2014.bin I've then tried to use it to carry-out a firmware update via the web interface menu -> Firmware Update -> Lacie-Firmware. Having clicked on "Start step 2" I got the following error:-
"Firmware upgrade step 2 started...
Firmware upgrade failed, upgrade process aborted, reason:
fw upgrade could not unpack firmware package, not a valid format"
Can I please have some guidance as to how to overcome this glitch?
EDIT
Having realised that one of the three downloaded .rar files was anomalous (different date - ditto the.bin file) I deleted all three, downloaded a fresh, matching set and extracted correctly-dated .bin file. Then tried once more to carry-out the fw upgrade. This time I got this error:-
"Firmware upgrade step 2 started...
Firmware upgrade failed, upgrade process aborted, reason:
fw upgrade MD5 check failed firmware image is corrupt"
I've downloaded and unpacked xfvdw-sl-16-0-nwsp2-30dec2014.bin I've then tried to use it to carry-out a firmware update via the web interface menu -> Firmware Update -> Lacie-Firmware. Having clicked on "Start step 2" I got the following error:-
"Firmware upgrade step 2 started...
Firmware upgrade failed, upgrade process aborted, reason:
fw upgrade could not unpack firmware package, not a valid format"
Can I please have some guidance as to how to overcome this glitch?
EDIT
Having realised that one of the three downloaded .rar files was anomalous (different date - ditto the.bin file) I deleted all three, downloaded a fresh, matching set and extracted correctly-dated .bin file. Then tried once more to carry-out the fw upgrade. This time I got this error:-
"Firmware upgrade step 2 started...
Firmware upgrade failed, upgrade process aborted, reason:
fw upgrade MD5 check failed firmware image is corrupt"