Why am I receiving the error "Activation Server Error - Code E_ACT_NOT_READY" ?

I cannot access my previously downloaded and purchased books. A real bummer because I need them for a homework assignment due tonight. I am receiving this error on a Macbook. Tried contacting Adobe, and they could not help. Does anyone know how to fix this? I was able to read my purchased books just last week on this app. 

Also, when I try to follow the solution steps posted to this community board, the app does not allow me to erase my authorization.