Check the box next to the certificate, set the Trust accordingly, add a Description if necessary.
Click Upload & verify the certificate was added.
Note: If using an Update Resource Download Location verify the updated TrustedCertList.pem file is copied from C:\Program Data\Bit9\Parity Server\hostpkg\ folder accordingly.
Additional Information
When replacing the App Control Server Certificate, that Certificate will automatically be included in the Trusted Communication Certificates list, and Trusted.
Currently it is not possible to delete a Trusted Communication Certificate.
Adjusting the Trusted Communication Certificates list will generate a new TrustedCertList.pem file which must be downloaded by the Agents.