IBooks buggy on my iMac

Question

I received an  iBook as a gift. When I signed in to iBooks it asked for the password for my Apple ID. After I put this in I clicked  on redeem.  Asked for my Apple ID password again. Nothing happened. I clicked redeem again.  It asked for my password once more. This was an endless cycle.  I then redeemed the book on my iPhone and downloaded it without a problem.  I opened iBooks on my iPad and also downloaded it there.  Went back to my iMac (both at the time and also the next day) hoping I could now download it since all devices shared the same Apple ID.  No luck.  In preferences "synch across devices" was checked.  I then also checked "automatic download."  However, if I quit iBooks and restarted it, the automatic download was
now unchecked although synch was still checked. Also, if I closed the app and re-opened it I was asked for my password again.  Since I don't do much reading directly from my computer, this is not a huge problem  However, being obsessive, these kind of bugs really get into my head and are most annoying.  Help would be greatly appreciated.

Answer 1

You don't need to replace them unless you had books that weren't downloaded from the iBooks Store. In that case, restore from the backup you made.
Please read this whole message before doing anything.
This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.
Step 1
The purpose of this step is to determine whether the problem is localized to your user account.
Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”
While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.
Test while logged in as Guest. Same problem?
After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.
*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.
Step 2
The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.
Please take this step regardless of the results of Step 1.
Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem. You must hold down the shift key twice: once when you turn on the computer, and again when you log in.
Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.
Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.
The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.
Test while in safe mode. Same problem?
After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of Steps 1 and 2.