Blank screen after payment on VM2.6.x

[admin]

Symptoms:
Blank screen after payment on VM2.6.x
Blank page after confirming order on VM2.6.x

Important note:

When updating to VM2.6.x you should make sure that the TCPDF library is compatible with VM2.6.x especially if you are using any 3rd party extensions which share the TCPDF such as Artio Invoice, CCVOAM or other. In case you experience a problem after installation of VM2.6.x you may want to follow this guide to disable Virtuemart's PDF functionality.

To disable TCPDF in VM2.6.x you may wan to:

1. Create a new order status:





2. Make sure it is the only status assigned here:


This new status should not be assigned by any of the payment methods to any of your orders, otherwise you may encounter fatal errors with the TCPDF incompatiblity.

Second option is to update TCPDF library in /libraries/tcpdf to a one that is supported by VM. In general we do not recommend to use solutions based on TCPDF unless
- they are triggered from cron or ajax context
- they have at least 512 Mb available PHP memory

Otherwise you may encounter these which all of them lead to white screen/fatal errors:
- memory leaks
- timeouts
- regex recursion limits

Best Regards,
Stan

[firepeet]

Hi Stan,

I have about the same problem. When I put a product into the Shopping Cart and I go to the Shopping Cart then I get immediately a blank screen.
Even after I've did your above advice. This is since I've updated yesterday to the latest version of VM.

Joomla: 2.5.22
Virtuemart: 2.6.6
OPC: 2.0.248.130614
ccVAOM: 3.4.2

When i disable OPC then i don't have this problem.

Kind regards,
Peter

[chillcreations@.....com]

Hi guys

ccVAOM does not share the TCPDF library of VM, we include our own copy.

Regards
David

[admin]

Hello friends, this issue most probably concerns Artio vm Invoice which shares the tcpdf library with VM and thus leading to version mitchmatch. It only occurs after confirmation of the order (depending on the resulting order status)

Peter, to find out the underlying error message, please enable VM debugging which enables error reporting and display in joomla on all pages that use virtuemart. Your issue is not related to the PDF problem because it only can occur after confirmation of the order.

Your issue may be related to
- some other part of your site is using the same class override then our opc solution
- some other plugin is loading virtuemart's config.php file without checkout if it was already loaded
- to limit the issue only to the shipping plugins, you may enable "delayed shipping" at the opc shipping tab which prevents loading of any shipping classes from the user context while cart page is loaded

this is common with 3rd party extensions that do not check if any other 3rd party extension had already loaded the class. To find out the problem you either need to enable the error reporting which would say which file is in the question and further we would need to check your site manually over FTP to see which plugin is in the conflict.

In very latest versions of OPC we had added a code that automatically renames /templates/YOUR JOOMLA TEMPLATE/html/com_virtuemart/cart/ in case 3rd party OPC solution is detected - it's so poorly written that once you disable it's helper plugins, you automatically get blank screen at the cart which prevents any other solution of using the cart. If this is the case, you can try to rename the above directory to anything else.

Please write us an email to info@rupostel.com and we can solve this directly on your site.

Best Regards, Stan