Device or computer could not be verified Recently I bought Macbook Pro Retina Early 2015, and after approximately one month my wifi shows 


  No Wifi/Wireless device found


I rush to the iStore and submitted my macbook, they serviced it and returned it to me, after approximately 2 to 3 days the problem was back again and gone after 2 days. Since my wifi is working perfectly. 

The problem I am facing is now when I open APP STORE and sign in there I get the following error message:


  Your device or computer could not be verified. Contact support for assistance.


I googled it search it on forums and got that its an issue of non registered network adapter. Kindly help me in this scenario is this a software bug or a hardware one or some effective solution.
Just had this problem. Not sure what exactly had helped, but I


Went to the Network Preferences and deleted whatever I could, all the locations except the one left and for this last deleted all the interfaces.
Rebooted
In the Network Preferences created a new location.


After that everything started to work again. Probably you could just delete and recreate your Ethernet interface.