Ibooks won't open at all.

You seem to have lost the near identical question you asked yesterday:

https://forums.developer.apple.com/message/53472

Try the following and stop when iBooks starts working again:

1. From Finder press shift+cmd+G and copy paste in the following:

   ~/Library/Cookies/com.apple.ibooks.cookies

2. If it takes you to a selected file, delete it, and test iBooks again.
3. Otherwise, from Finder again, press shift+cmd+G and copy paste in the following:

   ~/Library/Cookies/Preferences/com.apple.ibooks.plist

4. If it takes you to a selected file, delete it, and test iBooks again.
5. Otherwise, from Finder again, press shift+cmd+G and copy paste in the following:

   ~/Library/Containers/

6. Find com.apple.iBooksX and delete it.
7. Find Containers/com.apple.BKAgentServiceand move this one to the Desktop.
8. Log out and log back in. The book library will be empty. Rebuild it by downloading your purchases from the iBooks Store and importing any other content you added. You may find the added content in the folder named "com.apple.BKAgentService" that you moved to the Desktop.

-Max

Let us know what step you got to before iBooks started working for you again.

This is happening to me as well. None of the steps have any affect. Will eventually try another user account.