We've recently upgraded our SilverStripe site from 2.4 to 3.1 and installed the upgrade on a VPS.

The frontend appears fine, but when we log into the backend the page tree does not appear, but throws 'Bad Gateway' errors.

Looking at the AJAX URLs for these, they are:

/admin/pages/listview?locale=en_GB
/admin/pages/treeview?locale=en_GB

However, attempting to access other pages in the backend also results in Bad Gateway errors as well.

Reading up across the net people have suggested configuring nginx. We have PHP with Fast CGI enabled already. Any thoughts?

P.S. It may or may not be related, but strangely when we enable 'dev' mode, the admin user / password authentication does not seem to submit. It just repeatedly asks us for the username and password. We've triple-checked and it's correct what we provide it, so we've put the site into 'live' mode to access it, and now we're dealing with the Bad Gateway errors appearing in the backend.

I don't think this is a SilverStripe problem, live mode might hide the problem, but underneath It's probably still there, preventing you from logging in.

Googling shows lots of problems like this on nginx. Maybe this one might help? http://stackoverflow.com/questions/10003978/php-fpm-and-nginx-502-bad-gateway

You probably already seen everything, sorry I can't be of more help.

Hey martimiz,

Thanks for your reply. The Bad Gateway errors come and go in live mode - this morning they were gone. We are still unable to log in when enabled 'dev' mode.

Given the site is running on a VPS, perhaps this has something to do with it? I agree this is not a SilverStripe issue. We will continue to monitor closely and report back if we find anything, anyway.

In the meantime, I found this other post on the forums which may steer other members in the right direction:

http://www.silverstripe.org/community/forums/general-questions/show/24143

Thanks!