The problem is that your Hac doesn't think it has an internal network interface. This can be because you don't have one, the ethernet driver you have doesn't recognize your hardware, or even if you're using a VPN or Proxy (according to an Apple Engineer I opened a case against recently).
On your Hac this can be circumvented by a couple of ways.
Most common is to have this stanza in your com.apple.boot.plist:
<key>EthernetBuiltIn</key>
<string>y</string>
If you have that and it still isn't working, you may want to generate a device property ID for your ethernet device.
One of my Hacs is fine with a change to AppleYukon's plist to allow my on-board ethernet (Shuttle SX38P2 system) but another Hac I have (Dell Optiplex 755) needed a device-property added to my com.apple.boot.plist:
<key>EthernetBuiltIn</key>
<string>Yes</string>
<key>device-properties</key>
<string>450000000100000001000000390000000100000002010c00d041030a040000000101060000197fff0400160000006200750069006c0074002d0069006e0000000500000001</string>
Do not blindly add that device-properties string to your com.apple.boot.plist. I think it also includes my nvidia 9800 in there, that Dell is a bit of a basket-case and I had to get explicit.
You can find out how to generate your own Device-Properties for your ethernet device or any other device by searching in this forum.
There are some people that have just deleted their network devices from the Networking pref pane and then re-created them with success, but that method never worked for me, I had to generate a Device-Properties string for it before it would let me use the App Store.
Good luck!
Once you have your Ethernet device realizing that it is an internal device, you'll be fine.