I have upgraded my drupal website from version 6 to 7 (db and themes as of now). When I click on some of the views, I get a popup with the following message

An AJAX HTTP error occurred.
HTTP Result Code: 200
Debugging information follows.
Path: /swj/admin/structure/views/view/UnderReview/preview/page_1/ajax
StatusText: OK
ResponseText:
Fatal error: Call to a member function is_defaulted() on a non-object in /Applications/XAMPP/xamppfiles/htdocs/swj/sites/all/modules/views/includes/handlers.inc on line 212

When I ignore the above message and save the view (after adding a field), I get the following message on a white page

Fatal error: Call to undefined method stdClass::save_row() in /Applications/XAMPP/xamppfiles/htdocs/swj/sites/all/modules/views/includes/view.inc on line 1632

I think the above fatal error message could be because of the AJAX error. I get the AJAX error whenever I try to add a field, modify page settings or update preview.

for the "Fatal save error", the following is the log message

Notice: Undefined property: stdClass::$display_plugin in view->init_display() (line 320 of /Applications/XAMPP/xamppfiles/htdocs/swj/sites/all/modules/views/includes/view.inc)

I have installed the latest stable versions of views, ctools and also ran update.php

Is there something that I can do to fix this?

Thanks in advance.

Regards,

Raghava.