No upgrades available / latest version not available

Symptoms

• License check fails (error message shown in System Settings)
• An error is displayed under the dropdown where new versions are listed.

Cause

1. The license check fails.
2. The update repositories are unreachable.
3. You are trying to upgrade from a very old version, which no longer trusts the modern TLS/SSL certificate.

Resolution

These are the main reasons for upgrades not being available:

• If you are still on version 5.1.3 or lower: Reach out to support. 
  Most likely, your outdated product version does not trust the modern SSL/TLS certificate of our upgrade repository.
   
• It is required to upgrade to intermediate versions first.
  For example, if the version is still 5.3.3, it's necessary to upgrade to 5.4.4 first before 5.5.1 will be available to download.
• There's a connectivity issue. Verify with a tcpscan if a connection is possible to port 443 of these hosts.
  More info: How to perform a port scan (tcpscan/udpscan)
  
  From Parallels Secure Workspace 5.6 onwards: Before:
  • awg.parallels.com
  • psw.parallels.com
  • lic-val.awingu.com
  • repo-pub.awingu.com
  • repo-us.awingu.com
  • repo-eu.awingu.com
     
• The license key does not include active maintenance & support.
  Organizations are entitled to upgrades released within this specified period.
  Validate this under System Settings. Immediately upon signing in, the license details are shown.
  Otherwise, navigate to System Settings > Global > General info.
  
  See the screenshot below. Press the [Check license] button to be sure whether the license is still valid.
  • The maintenance & support is just expired.
  • A new license key was not imported yet.