Problems with Plesk control panel licensing

It seems that the Plesk control panel on one of our servers is having issues connecting with Plesk's licensing server recently. 

You may be unable to login to the Plesk control panel and see a message about licensing such as: Error: The license key is invalid. In order to use Panel, please obtain and install a new valid license key. 

We are aware of this problem and our service provider will manually re-provision the license until the issue is resolved.

Please contact us if you urgently need to access your Plesk control panel and experience the above problem.