OS X El Capitan installation error: AMD-Action:authenticate:SP

When doing a clean re-installation of El Capitan (highest supported version) from a bootable USB on an older Mac (MBP, 15-inch, Late 2008), I get this error:

An unexpected error occured while signing in.

AMD-Action:authenticate:SP

The error shows up, while logging in with the Apple ID into the App Store in the installer.

• I tried with different Apple IDs,

• Also tried running these commands in the Recovery Terminal and restarting:

  csrutil clear

  csrutil enable

Solution 1:

The problem was that the old Mac did not have its date set correctly.

1. Hold Option (ALT) + Command + R at Mac startup to start internet recovery

2. Going into Utilities > Terminal starts the recovery terminal

3. Run date mmddHHMMyy - this solves the problem (date must be in PST!)

4. Run csrutil enable

5. Run csrutil clear

6. Exit the recovery terminal and continue OS X installation normally.

Here is the full step-by-step solution to solve the problem.

Solution 2:

For me, the problem was because I did not have access to the Shared folder under Users in the primary drive. When i changed permission for the Shared folder via 'Get Info>Folder permission>Set to read', the problem was resolved..

Hope this helps