New version of ShoreTel server can’t connect

The upgraded version of ShoreTel 11.0 server works fine with no issues at all. So I tried to install it to the new ShoreTel communicator to end-users and to our Citrix / Remote Desktop Servers. When I log in without administrator/user permission in Citrix and run the new client, I get the following error message: "Encountered error while attempting to connect to server."

Why is this so? Is it not supported anymore? Please help. Thanks in advance.
