error during autentication

Hi, i have Windows 8.1 pro and the iCloud client always worked fine.

Now is not working !

I can log to icloud.com with my id and pw without problems, but when i try to activate the iCloud client with id and pw, i recive an autentication error !

If i intentinally put in wrong pw, i receive the pw/id error so i'm sure that pw and id are correct.

I reinstalled the client, changed the id password... nothing working !

Autentication error !

Help !