Issues with activating license

When activating license with license key I get the following message    -  eM Client doesn’t have a valid license. You can get access to off-line data, but on-line synch and sending mail is inactivated. When license is received, you will be able to use the product without restrictions again.  How could this be solved?

Is this a free license or a Pro license?

It is a free license

It seems like everything is working now, since I managed to confirm my e-mail adress.