500 error when logging into backend (held on a subdomain)

[eluser]itsdanprice[/eluser]
I have a website that has been setup and working fine for ages. It's built using Code Igniter. It's run using .htaccess files to restrict access and hide urls. All fine.

Until a couple of days ago when we try to access http://admin.dealersupport.co.uk we get a 500 error (this is the back end of the site, held in a seperate subdomain.) Nothing else has changed on the server. I have tried restoring from a back up from when I know it was working. The problem persists.

The only thing I can think of is that we recently upgraded to Plesk 11.0.9 and since then we have been seeing some Apache instabilities.

The only thing that is thrown up by the error logs is this:

Wed Nov 21 08:40:17 2012] [error] [client 94.31.24.129] Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden: /var/www/vhosts /dealersupport.co.uk/admin/index.pl, referer: http://admin.dealersupport.co.uk/login

I have now added this to my .htaccess files

> Options +FollowSymLinks +SymLinksIfOwnerMatch
> RewriteEngine On

And that seems to have eliminated that error from the error logs, but we are still getting a 500 error when we have logged into the backend.

We have updated to the latest version of CodeIgniter.

Can anyone help?

[eluser]itsdanprice[/eluser]
Just as an update I have discovered that I can access the different areas of the backend by going to

http://admin.dealersupport.co.uk/mybackendarea

It seems I just can't access the base url:

http://admin.dealersupport.co.uk/

What could this be?

It won't let me submit articles from the backend. I get the same 500 error

[eluser]itsdanprice[/eluser]
Can anyone help? I'm tearing my hair out here.

I'm thinking its something to do with the controllers, when I try and use functions seems to be where it falls down...

[eluser]itsdanprice[/eluser]
Managed to get it to produce this error:

Fatal error: Uncaught exception 'Exception' with message 'GAPI: Failed to request report data. Error: "GDatainsufficientPermissionsUser does not have sufficient permissions for this profile."' in /var/www/vhosts/dealersupport.co.uk/admin/application/third_party/analytics/gapi.class.php:218 Stack trace: #0 /var/www/vhosts/dealersupport.co.uk/admin/application/modules/analytics/libraries/analytics_lib.php(86): gapi->requestReportData('20924509', Array, Array, Array, NULL, '2011-12-23', '2012-11-23') #1 /var/www/vhosts/dealersupport.co.uk/admin/application/controllers/home.php(34): Analytics_lib->get() #2 [internal function]: Home->index() #3 /var/www/vhosts/dealersupport.co.uk/admin/system/core/CodeIgniter.php(359): call_user_func_array(Array, Array) #4 /var/www/vhosts/dealersupport.co.uk/admin/index.php(202): require_once('/var/www/vhosts...') #5 {main} thrown in /var/www/vhosts/dealersupport.co.uk/admin/application/third_party/analytics/gapi.class.php on line 218

[eluser]itsdanprice[/eluser]
So I have removed analytics I can get to the page
http://admin.dealersupport.co.uk now.

Still can't submit articles.

Get this error:
Fatal error: Cannot access protected property MY_Form_validation::$CI in /var/www/vhosts/dealersupport.co.uk/admin/application/modules/news/controllers/news.php on line 459

This points to line:

Code:

$this->form_validation->CI =& $this;

I have tried commenting this out and it seems to work, however nothing appears at the front end