Agreed! Problems are indeed always annoying.
The Application Manager took a fair share of these, but currently it appears to be functioning OKAY; sometimes slow, but OKAY. If there is no reaction after you have entered your user-id and password, it may be that it cannot contact CL, maybe good to check whether it is being blocked by the firewall?
Do you have PD up and running? Have your credentials been accepted there? If something is wrong with them you will get a message.
Upgrading drivers is sometimes unavoidable. And we have begged Cyberlink to come with function that allows users to go back to a previous version, should to new cause problems. I guess that you have shared your problems with CL technical support?