Why does the proxy server give a 402 Payment Required error when accessing the site?

Question

Computer networks

When accessing one of the state sites, the proxy server logs (ISA-2006) give out such crap.
And on the browser page, this is .... The custom error module does not recognize this error.

Answer 1

It seems to me that your proxy (aka firewall) does not process correctly, or even blocks the return traffic of the target host. Maybe Mrs. the office with you wants to https, but the proxy does not give it, or with the permission of another type of http headers used by the target host in the responses, it's a problem.
There is another option - all the same, a 402 error, this is a "Payment is required" error, but you do not agree and use a paid resource!?