This error message is displayed if the Redgate Client Service is stopped or unavailable and can sometimes occur when activating your Redgate products on your computer. 

Troubleshooting

• The problem is usually that the Redgate Client Service isn't running or has gotten into a bad state. Open your Services console (Control Panel > Admin Tools > Services), locate Redgate Client in the list of services, right-click, and choose Start or Restart.
• You may need to update your version of the Redgate Client. You can get the latest installer here.
• It could be that your computer is protected by a firewall/antivirus software and restricts what the service is allowed to do. Please allow the endpoints listed in this article: Licensing & update URLs to add to your Allowlist in firewall.

If none of these steps resolve the problem please send the latest full Redgate Client Logs which can be found in C:\ProgramData\Red Gate\Shared Client\Log to Redgate support.

Related article: Install Fails Because RedGateClient Failed To Start