Are you running Spybot as an administrator?
You can do this by right-clicking the Spybot icon and choosing the option to "run as administrator". This must be done to give Spybot the permissions it needs to function correctly.
If this does not work, this could be a proxy issue.
Please go to:
Start Center > Settings (tick "Advanced User Mode" if you do not see "Settings") > Internet Protection
In Internet Protection, please untick "Use Spybot Proxy" and "Use own proxy to download updates" if either of these is ticked.
Click "Apply" and "OK" and restart Spybot.