Error when trying to add a product in Main menu

[chris88]

Hello,
After upgrading to virtuemart 2.0.12f from 2.0.12b i have a problem when i try to assign a product in main menu. I try to create a new virtuemart product detail layout in main menu, but i get this message in the right place of the page under basic parameters: Fatal error: Cannot access empty property in \libraries\joomla\registry\registry.php on line 194. I never had any problem with this in the past and i am sure i haven't messed with anything after the update to 2.0.12f. I cannot move on creating the product layout so please help me.
Thank you

This is the line 194:
      
$ns->$nodes[$i] = new stdClass();

[chris88]

Please guys i need help.