• In the Horizon Administrator dashboard, the Composer service has a red indicator with the error:
The service is not working properly.
  • When attempting to access a linked clone pool in Horizon Administrator, the following error can be seen:
The certificate configured on View Composer Server is invalid, blocking communication with this server. To resume communication, replace the certificate with a valid certificate signed by a CA. Alternatively, accept the certificate thumbprint by clicking Verify in the View Administrator dashboard.
This issue occurs during the Horizon Composer upgrade, the option "Create default SSL certificate" was selected.
  1. In Horizon Administrator, navigate to View Configuration -> Servers, and Edit the vCenter Server entry associated with the Composer service.
  2. Click Edit in View Composer Server Settings
  3. Follow the prompts to verify and accept the new self-signed certificate.
  4. Access the dashboard and confirm the service is now showing as "green" and you can manage the linked clone pools once again.
  5. For steps to replace the self-signed certificate with a signed certificate, please see:

If the issue is not resolved, look in the logs for more details on what else could be wrong.

On the Connection Server, see:


where "YYYY-MM-DD" is today's date.

On the Composer server, see:

C:\ProgramData\VMware\View Composer\Logs\vmware-viewcomposer.log