This post bij Dan537 help me solve it:
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Had this problem as well once I was deep into the process and could not log into the App Store.
Here is what worked:
- On another Mac computer I own I logged out, then into the App Store.
- On the Mac I was having this issue with I went into Internet Recovery (power on or restart and hold Command-Option-R immediately when you hear the startup chime). Keep holding until your see the Starting Internet Recovery globe icon. You should then get prompted to join a Wi-Fi network if you are not on wired Ethernet. Once joined, you should see a progress bar, then the OS X Utilities screen, where you can choose Reinstall OS X. It can take quite a while for this to appear, since it is loading from Apple's servers over the Internet.
- This time the AMD-Action:downloadProduct:SP message did not show up and everything proceeded normally.
Hope this works for folks.
Got this from Cory Cooper posting on Mac-help.com - Many thanks Cory!!!
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