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.

If this doesn't 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