Network Error when invoking Google Now When I try to invoke Google Now by swiping up from the Home button, I get the message "Network error.  Check your network connections and try again".  I have a solid WiFi signal, and searches from the search bar work fine.
I get the same message when I go into settings after launching Google Search and try to enable Google Now.

ASUS Transformer Prime,  Android 4.1.1
Finally found the answer.   I had four Google accounts - one of them could not sync because it required domain policy to be enforced, and I hadn't allowed that.   I connected the tablet to my laptop and used adb logcat to see what was being logged when the error was displayed:

I/GLSUser (28125): GLS error: DeviceManagementRequiredOrSyncDisabled &lt;&lt;account name redacted&gt;&gt; oauth2:https://www.googleapis.com/auth/personal_derived_data https://www.googleapis.com/auth/paths.notifications
V/GoogleLoginService(28125): Returning error intent with: ComponentInfo{com.google.android.gsf.login/com.google.android.gsf.login.LoginActivity}
E/Velvet.VelvetNetworkClient( 4564): Failed to get auth token


(these messages were repeated several times).

I guessed that the errant account may have been involved (even though it was not the account I was trying to active Now with), removed the account from the device and all is well.