Catalogue > Manage products > edit product page - blank

[waynerox]

When I log into the backend and navigate to Catalogue > Manage Product everything is working fine. When I click on a product I get a blank page, with a link to 'Create new video' and 'Add an attribute'.

Our setup is: Magento 1.8.1, ubuntu 12.04, nginx php5-fpm and varnish.

My nginx log is displaying this error:

*6711 FastCGI sent in stderr: "PHP message: PHP Fatal error: Call to a member function __toString() on a non-object in /var/www/clients/client1/web2/web/app/Mage.php on line 859" while reading response header from upstream, client: 82.71.243.141, server: www.example.com, request: "GET /index.php/admin/catalog_product/edit/id/801/key/918d6b60004194117d8783613d066922/ HTTP/1.1", upstream: "fastcgi://unix:/var/lib/php5-fpm/web2.sock:", host: "www.example.com", referrer: "https://www.example.com/index.php/admin/catalog_product/index/key/bcc1f51a9f74e1f425be8d93903f0949/"

Can anyone help with problem as I'm really stuck?

[Daniel Sousa]

on line 859:

replace:

self::log("\n" . $e->__toString(), Zend_Log::ERR, $file);

with:

self::log($e, Zend_Log::ERR, $file);

Then try to reproduce again the error and check your log files.