Problem with latest firmware update with Passport Wireless

I tried to My Passport Wireless with Firmware 1.05.01with the latest v 1.06.06. I used Passport wireless dashboard for upgrading. I get the message," Device does not have enough space for upgradation". I tried other methods -manual. Same message comes. Can someone help?

Hello, try performing a system only factory restore, this will not delete the information but it should remove any issues that the OS might have, then, try updating the firmware manually.

Hello Iluna,Thanks for your suggestion. 1.As suggested I did 'Factory Restore" and I tried to install the firmware from mypassport dashboard. I still get the same message-“Device does not have enough space for upgradation”. After factory restore also I see the OS version as v1.05.01.2.I downloaded the upgrade and tried to install it manually. Again the same message.3.I tried to upgrade it from mobile device -iPhone5. I got the following message: “Firmware upgradation failed”.
I never faced this problem till the last upgradation. The device is working normally.
Any other suggestion please?
DCM1944