• A blank page loads when going through the proxy.
• Site does not load.
• URL does not load.
• Site only partially loaded.
• Page cannot be displayed.
• Getting Policy Denied

Policy Trace and Packet Capture are needed to get a full picture of traffic-related issues. (This supporting data is required for a Service Request)

Policy Trace
How to use policy trace to debug access issues

Packet Capture
Using packet captures - Quick start guide

Upload sysinfo, event logs, and other required files to case
How to send service information from a ProxySG to Symantec Network Protection to update a Service Request?

The below techniques can be used to identify slow or failing URLs for use in data collection filters.

• URL in the browser address bar
• If the trouble is with a link, hover over the link to check the full URL.  Take a screenshot or make a note of it.  Right click>Properties can also show the resource.
• If the object not loading is an embedded object on the page, right click on the page - view html source.  The objects on the page should be visible in the source by filename or url.
• Press F12 in your browser or another shortcut to run Developer Tools
• Under Debugging, press the Pause button with 2 bars in it, and make sure the page is set to Never Break on Exceptions
• Go to the Network tab and make sure it is recording
• Refresh the page
• Look for denied resources or failed authentication challenges in the HTTP Response column and identify the resource that was requested and the response
• Look under the Console tab for failed resources that were called by a script rather than the browser.

Other related solutions:

"Unknown" content in SYN packet causes some websites to refuse connections to ADN enabled web-gateway proxies

Some web pages load slowly, or a blank page loads when going through the ProxySG appliance (RFC 1323)

Flash Video does not play when going via a Proxy.