When I started the program today, I get a message say "eM Client doesn't have a valid license."

I need help fixing this problem.

Same thing just happened to be this morning, been using em Client without problem for quite a while.   Following!

Me too - wow, this is a biggie - failing on all three systems for which I have a valid paid license - time to look for a new mail client?

Dear users,

During the last hour some of you experienced an issue with eM Client licence activation. Your licence was deactivated and it was not possible to re-activate it for some time. The issue was caused by an error in our Licensing system and we worked hard on a quick fix. 

By now you should be able to continue using eM Client. 

We apologize for the inconvenience.

Russel Markosky
eM Client