Most likely, the error occurs because your license has expired. To fix the error:

1. Check the license expiration date. See this detailed guide for instructions.
2. If the license has expired, renew it. To find out how to renew a license, see this article.
3. If the license has not expired, check that the system date is set correctly on your computer. If the system date is wrong, adjust it and try to activate the application once again.

If the issue persists, send a request to Kaspersky Lab technical support via My Kaspersky. In your request, please provide a detailed description of the problem.

For instructions on how to use My Kaspersky, see the Online Help page.