Communication problem with license server E_ACT_NOT_READY

Hello, 

I cannot open books in my library and cannot open a new ebook I bought yesterday evening in Adobe, I get this message, in Dutch, the English message is visible in the subject: 

"Communicatieprobleem met licentieserver:

E_ACT_NOT_READY"

How can this be solved?

Many thx

Jurjen