Installed Maverick and iBooks does not work. Any ideas?

Hello. I installed Maverick and iBooks app does not work.

Whenever I launch iBook and get the following message:

a) There is no space to signin.

b) Whenever I click on Sign In the message just pops back up.

c) Whenver I click on Cancel and Create Apple ID again the message just keeps popping back up.

I am already signed in to iTunes and iCloud, so am not sure what I am doing wrong.

I already re-installed iBook and it is still doing the same thing.

Really appreciate any help here.