You may experience the following error while trying to add vCenter to Citrix Studio:
"Cannot connect to the vCenter server due to a certificate error. Make sure that the appropriate certificates are installed on the vCenter server, and install the appropriate certificates on the same machine that contains all instances of the host service.“
Install the rui-ca-cert.pem to the LOCALCOMPUTER/THIRD PARTY ROOT CERTIFICATION Store on the Delivery Controller (also called the DDC).
If you are running vCenter on Windows, you will need the cacert.pem, usually located at C:\ProgramData\VMware\VMware VirtualCenter\SSL\cacert.pem.
The Delivery Controller is the one that has to authenticate against the vCenter.