MB Air: connect, update App Store with broken Wifi/Airport via USB WiFi On my MB Air 2,1 (mid 2009) the wifi is broken. Connecting with the internet is possible via an Apple USB-Ethernet-adapter.

When trying to install an app/update via the App Store (e.g. to OSx El Capitan) the message in App Store is:


  Your device or computer could not be verified.


It seems to me a working Wifi Airport Card is a prerequisite for connecting/authenticating with the App Store. 


Can anyone confirm this is the issue?
Is a work around available?


Otherwise I've googled a bit and as far as I can tell the options for this 6 year old machine are either to have the wifi repaired (€125) or buy a USB wifi dongle (€22) and accept that OSx will not be able to update. 

Cf. e.g. this post:


  A NIC (network interface card) is needed for authentication purposes to make sure the computer is what it claims to be.


on forums.macrumors.com reads like a sound argument.
repair wifi card or logic board then You will can log in usb wifi dongle or ethernet cable won't work. I know this is ridiculous.