Digital editions not working

Every time I try to borrow a book from the library, I get the error message: 'Cannot connect to fulfillment server. Please check your internet connection'

I have checked my internet connection

I have checked my firewall

I have deauthorised and re-authorised my computer

I have uninstalled and reinstalled DE3

I have tried to install DE4.5

When i try to download 4.5, I get a pop up that says: 'This is a binary file. Would you like to Save or Cancel'

I save the file and then go to downloads, when I click on the 4.5 version download, nothing happens. So I reinstall version 3.

I am able to purchase books from Kobo but I still not able to borrow books.

Can anyone tell me why this is happening? Or at least give me some advice on something else to try.