Proxy.pac no longer works after upgrade(s) ...

[Christopher Savas]

Long story short: I've been in my current office for just a couple of
months, and dropped on my desk was a project that has been passed from
one person to another for probably about a year now. Apparently,
around the same time there were numerous new roll-outs and upgrades
(MSIE7, a new version of Java, servers being upgraded from 2000 to
2003, etc.), the local proxy file quit working.

I've downloaded a copy of the proxy.pac file from our Corporate server
and opened it in Notepad, side by side with the local proxy.pac file
that we publish to an internal web server here and apply to restricted
accounts via GPO on login. The GPO applies the proxy.pac file, but it
doesn't work - sites that are allowed never show up (you just get a
"Page cannot be displayed" error eventually), and sites that are not
allowed, which should re-direct to a locally stored "Email your
Director to get this unblocked" type of page behave the same way -
"Page cannot be displayed."

I can't find any difference between our in house system & the
Corporate one, and this thing died long before I came on site, so I
have no idea what change (of the many) preceeded it. Any thoughts /
help / input?

 

[Rob]

Christopher Savas <savas.christopher@gmail.com> wrote:
> Long story short: I've been in my current office for just a couple of
> months, and dropped on my desk was a project that has been passed from
> one person to another for probably about a year now. Apparently,
> around the same time there were numerous new roll-outs and upgrades
> (MSIE7, a new version of Java, servers being upgraded from 2000 to
> 2003, etc.), the local proxy file quit working.
>
> I've downloaded a copy of the proxy.pac file from our Corporate server
> and opened it in Notepad, side by side with the local proxy.pac file
> that we publish to an internal web server here and apply to restricted
> accounts via GPO on login. The GPO applies the proxy.pac file, but it
> doesn't work - sites that are allowed never show up (you just get a
> "Page cannot be displayed" error eventually), and sites that are not
> allowed, which should re-direct to a locally stored "Email your
> Director to get this unblocked" type of page behave the same way -
> "Page cannot be displayed."
>
> I can't find any difference between our in house system & the
> Corporate one, and this thing died long before I came on site, so I
> have no idea what change (of the many) preceeded it. Any thoughts /
> help / input?

There was an error in IE that caused trouble with this kind of
proxy setup. Basically the IE failed to parse correct files.

It was fixed with a Hotfix from Microsoft.