PHP Fatal error: Call to a member function get_option() views/includes/view.inc on line 2493 I installed the Carbide Builder Module from SooperThemes and now receive this error when trying to go to any node/add page. 

Their support says one of my Views displays has a view with a missing display plugin.

I have a lot of views/displays. How can I find it easiest?

UPDATE: Looks like there are some old Views from a D6 installation uses Feeds.
Enable the Devel module and insert a ddebug_backtrace() statement before the line containing the get_option() method call. It should print out a stack trace that you can follow to some view id.