You may have noticed a web site not open properly through web gateway or the expected menu/page get blank result instead of expected content. Like this sample below:
By click on sign-in(1) it is expected to get a form in Area 2.
Troubleshooting in Chrome
In order to understand what happen on this web page white it load the content you can enable Developer Tools (Option > More Tools > Developer Tools). This will provide you additional informations on errors that might happen when the web site is loading.
Choosing "Console" tab you can easily identify many syntax errors with a link to the area it is pointing to on the right.
Here you can verify the content that has been delivered which is the default progress page triggered by the web gateway.
Root cause of this issue
To understand why web gateway deliver us Progress Page instead of expected content we need to check related rule set.
This mean in case the content which loaded over a time period of 5 sec will get 307 response and been redirected to the WebGateway Progress page. Knowing our setup we can create exception for this web page before Progres page will be triggered.
As possible solution you can create new rule in front of Progress page rule using the Action of "Stop Ruleset" in order to stop all rules been further processed in the same rule set. Our aim is only avoid Progres page from been triggered. All other rules like AV and URL filter will still apply and scan/block if required.
This is simple sample created by URL.Host criteria for whole web site you can also use URL.Raw in case you plan to whitelist only specific URL path and not whole web site. The result can be checked also in Ruleengine Trace. Now you should see a match for your new rule instead of matching into "Progress Page"-Rule.