The License for a deployed application has expired

This is the error we are getting. Your license key for ComponentPro.Ftp is expired or used for an older version. Please contact ComponentPro Sales Team at sales@componentpro.com. If you already have a license, please log in to our portal at https://www.componentpro.com/account to apply the license key shown on the account dashboard page. After working for several months, we are now getting this error on a deployed windows service. The license is less than a year old. What has happened?

I see an answer to exact same issue as follows, and that is of absolutely no use. "Please check if you have set the license key you got on your portal Dashboard correctly." The mechanism given to set the license is in the code and it was working for several months before it stopped or marked as expired. ComponentPro team: Please help with a resolution.