I cant open my ebooks

I am unable to open my ebooks on my google chromebook or iphone. Ive tried deleting and redownloading, deauthorizing, downloading with a different browser, and nothing seems to work. I keep getting two different error messages: 

Error getting License. License Server Communication Problem:

E_ADEPT_NO_TOKEN 

and 

Error getting License. License Server Communication Problem:

E_ADEPT_DATABASE

anyone know how to fix this??