Have you installed SharePoint Foundation with Search Express? Don't panic if you see this warning message in Central Admin. Below is an explanation from Microsoft along with the Workaround.
This is a false alarm. It is not time bombed and your farm will continue to work. If you click on the health analyzer warning you will see
"Explanation : The licensing information not available". The MSSx sku does not have licencing module since its a free product. By default the rule "Trial period for this product is about to expire." is enabled in the health analyzer. The bug here is that we didn't disable this rule. The rule kicks in and its unable to find the licensing module and throws an exception (you can find it in the LOGS folder).
Workaround: In central admin go to "Central Admin" => Monitoring => "Review Rule Definitions" => click on "Trial period for this product is about to expire" rule under configuration and edit it. Uncheck the "Enabled" checkbox.