Is the Client on the same network as the Camera and Gateway?
If they are on different subnets you will have to use the gateway as a proxy for the camera.
Turn on the proxy in the Ignition Config file or check if already there…
Under Java Additional parameters add…
wrapper.java.additional.10=-Dvision.urlproxy.enabled=true
In the designer have the URL point to the proxy first…
http://[gateway IP]:8088/main/system/urlproxy?url=[camera url]
hope this helps
cheers