Can't understand Error Activation

I downloaded Adobe Digital edition 3.0 at first i can authorize my computer but i cant add the ebook that i purchased. So what i did I changed my Adobe Id and entered it again to authorize my computer It did authorize my computer but when i am adding my ebook there is an Error ! Check activation. i can't understand this.

What happen next was I can't authorize my computer anymore.. Any solutions for this? Thank you.