Proxy server breaking AJAX website on internal network

Question

I have built a website which uses ajax for most of the sites functions although it can fall back to standard page loads and form submissions if javascript isn't available.

The site has been tested across various browsers and operating systems and no problems exist although the client is unable to use the site because of blocking javascript errors.

The problem has been isolated to the Novel BorderManager proxy being used on their network, I have eliminated caching as the cause of the problem and I am not at a loss as to what to do.
I don't have access to a computer on the network to test for myself, all I am working with are reports from the client. One of the reports mentioned that the Google Analytics code on the page wasn't loading either.

Does anyone have any ideas as to what the proxy could be doing that would cause a problem like this?

Thanks

Answer 1

I am going to answer my own question incase anyone comes across this issue.

After visiting the client and running some tests on the site the issue turns out to be a cookie size issue. The Novel BorderManager seems to be blocking any cookies over 1.7kb.

Answer 2

all I am working with are reports from the client

Not an answer to your question, but that is probably not going to be enough. I would consider going there, requesting VPN access, or using a remote control software to look at the actual error messages output by the browser.

Alternatively, if none of this is an option, ask the client to copy & paste the browser's error console output.... Although the problem might be in files failing to load, for which you would have to look at the contents e.g. of Firebug's "Net" tab.