My Ibooks application will not connect to the iBooks store

Question

my iBooks application will not connect to the iBooks store

Answer 1

Launch the Keychain Access application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Keychain Access in the icon grid.
In the upper left corner of the window, you should see a list headed Keychains. If not, click the button in the lower left corner that looks like a triangle inside a square.
In the Keychains list, there should be items named System and System Roots. If not, select
          File ▹ Add Keychain
from the menu bar and add the following items:
/Library/Keychains/System.keychain /System/Library/Keychains/SystemRootCertificates.keychain
Open the View menu in the menu bar. If one of the items in the menu is
          Show Expired Certificates
select it. Otherwise it will show
          Hide Expired Certificates
which is what you want.
From the Category list in the lower left corner of the window, select Certificates. Look carefully at the list of certificates in the right side of the window. If any of them has a a blue-and-white plus sign or a red "X" in the icon, double-click it. An inspection window will open. Click the disclosure triangle labeled Trust to disclose the trust settings for the certificate. From the menu labeled
          Secure Sockets Layer (SSL)
select
          no value specified
Close the inspection window. You'll be prompted for your administrator password to update the settings.
Now open the same inspection window again, and select
          When using this certificate: Use System Defaults
Save the change in the same way as before.
Revert all the certificates with non-default trust settings. Never again change any of those settings.