After moving the coordinator server to another server, or performing an in-place upgrade, the web client no longer works.
The client port is hard coded to the web.config file so any uninstall/reinstall or moving of the coordinator will change the ports (unless statically assigned)
You will need to manually update the following file on the server you have the web client installed on:
C:\Program Files\Quest Software\ChangeAuditor\WebClient\Web.config
Look for the line that says:
<add key="Coordinator" value="servername:port"/>
Update the servername to be your new coordinator server and the port to be the port of that coordinator.
If you need to find the client port, it can be found here:
In the system tray on the coordinator server, right-click the coordinator icon and choose Coordinator status.
The client port line is the port that you will need to use for the web client.
Once this is done, the web client should work without restarting IIS
Also, make sure that if CA is recently upgraded, the client is upgraded, and CA is running after the upgrade.