PDF button in product details - Blank Page

[chrisrbk]

Hi all,

I'm using Joomla 3.3.6 and Virtuemart 3.0.6.2 and PHP 5.5.22.
I'm working on a Gavick template (shop and buy template), the site is multilingual (it/en).

I'm having a serious issue with the pdf button in the product details page.
When I click it, it shows me a blank page.
Sometimes I find this error in Chrome Developer tools: "Failed to load resource: the server responded with a status of 500 (Internal Server Error)"
In other pages with the same issue no errors, no messages, nothing at all.

Here's a link to a product page in my site:
http://www.easylabs.it/it/negozio/comunicatori/comunicatore-big-step-by-step-con-livelli-detail

Please could anyone help me?
Thank you very much,
chrisrnk

[jenkinhill]

Sounds like a lack of PHP resources. You should check the server error log - http://forum.virtuemart.net/index.php?topic=121692.0

[chrisrbk]

Hi jenkinhill,
thank you for your answer.

I already enabled vmdebug but nothing was shown.
Today I also set Global Configuration > Error Reporting to Maximum and finally a message is shown in the blank page after clicking the PDF button in the product detail page:

Fatal error: Uncaught exception 'RuntimeException' with message 'Invalid JDocument Class' in /web/htdocs/www.easylabs.it/home/libraries/joomla/document/document.php:305 Stack trace: #0 /web/htdocs/www.easylabs.it/home/libraries/joomla/factory.php(737): JDocument::getInstance('pdf', Array) #1 /web/htdocs/www.easylabs.it/home/libraries/joomla/factory.php(215): JFactory::createDocument() #2 /web/htdocs/www.easylabs.it/home/templates/gk_shop_and_buy/error.php(40): JFactory::getDocument() #3 /web/htdocs/www.easylabs.it/home/libraries/joomla/document/error/error.php(135): require_once('/web/htdocs/www...') #4 /web/htdocs/www.easylabs.it/home/libraries/joomla/document/error/error.php(107): JDocumentError->_loadTemplate('/web/htdocs/www...', 'error.php') #5 /web/htdocs/www.easylabs.it/home/libraries/legacy/error/error.php(791): JDocumentError->render(false, Array) #6 /web/htdocs/www.easylabs.it/home/plugins/system/redirect/redirect.php(134): JError::customErrorPage(Object(RuntimeException)) #7 [internal function]: PlgSystemRedire in /web/htdocs/www.easylabs.it/home/libraries/joomla/document/document.php on line 305

Unfortunately I can't understand what it means.

Please, could you help me?
Thank yu in advance,
Christophe

[jenkinhill]

Well that error all seems to come from Joomla. I see you have J3.3.6 and VM3.0.6.2 but these are old versions, for a start an update of VM is required for security reasons, see http://virtuemart.net/news/latest-news/469-security-release-vm3-0-8

Current versions to use are Joomla 3.4.1 and VM3.0.9 - but test on a backup copy of your site first. This may fix the problem, or it could maybe be related to your template.