Since I have upgraded OS X on my MacBook Pro to OS X El Capitan (10.11) and moved my users home folder to another partition as described in an earlier blog post, I was not able to sign into the Apple or iTunes store anymore via native applications. It was still working fine via the browser. The failure displayed was: “AMD-Action:downloadProduct:SP”. Yes, very helpful. No further link for help nor was I able to find anything about it on official support pages. Querying the web for a while I finallyContinue readingHow to solve Apple ID login failure: AMD-Action:downloadProduct:SP