Good afternoon, today I encountered the problem of a free license, the client went offline and cannot work, the free license has not expired

Good afternoon, today I encountered the problem of a free license, the client went offline and cannot work, the free license has not expired. Also, when entering the activation key, the client writes an error.

What is the error?

Did you recently get an email from eM Client informing you that they suspect you are using the Free License for commercial use?