On start up today had the error "eM Client doesn't have a valid license..."

Apparently eMclient stopped last week while I was on vacation and the error dialogue box says I need to obtain a valid license.  However my search under the message board indicates licenses never expire/are auto-renewing!

I have a licencekey but I do not eable to actify it.

Hello Jeff and Ruud,

Could you please specify exactly does the program tell you when you try to activate?

Thank you,
Maurice