It's a clients site, so I don't currently have access to the error logs, I can always ask for access.
The error message is:
The connection was reset
The connection to the server was reset while the page was loading.
The site could be temporarily unavailable or too busy. Try again in a few
If you are unable to load any pages, check your computer's network
If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web.
Other pages for the site work. Indeed the page prior to sending the script works. The script is tiny, it shouldn't be timing out or anything like that. I shall go back and double check the script, perhaps there is some error there.