Jira hosted in Windows environment shows "The product license you're using is not legitimate. Contact your license issuer." warning for valid licences

Issue Summary

After upgrading Jira to version 8.18.0, there is a warning on the header with the following message.
There is no functionality impact besides the non-dismissible warning. The problem is caused by a bug in the license validation library.

The product license you're using is not legitimate. Contact your license issuer.

Steps to Reproduce

1. Upgrade Jira to version 8.18.0
2. Locate the warning message on the header

Currently, the problem can only be reproduced in Jira hosted in a Windows environment. For those experiencing this problem in Linux environment, please raise a support ticket with Atlassian Support.

Expected Results

No warning regarding product license upon successful upgrade.

Actual Results

Warning message added on the header.

Workaround

Credit to gschoch@gs-soft.com

1. Navigate to …\Atlassian\JIRA\atlassian-jira\WEB-INF\classes\templates\jira\webpanel\notifications and create a backup of the "banner.soy" file
2. Open the "banner.soy" file
3. Remove the following new section (introduced in with the latest release of JIRA)

   /**
   * Render a forged license detected banner
   */
   {template .licenseForgedBannerMessage}
       {call aui.message.warning}
           {param content}      
               <div id="license-banner-content">
                   {getText('admin.license.banner.forged.warning')}
               </div>     
           {/param}
       {/call}
   {/template}

4. reboot JIRA