White screen and fatal error while attempting to visit the "block" admin page

Hi,

I've installed a fresh Drupal 6.9 version with new Views 6.x-2.x-dev (release 30. Jan).

When I try to reach the "block" admin page, I receive the following error with a white screen:

Fatal error: view::destroy() [<a href='function.view-destroy'>function.view-destroy</a>]: The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition &quot;views_plugin_display_default&quot; of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition in C:\xampp\htdocs\c-lounge\sites\all\modules\views\includes\view.inc on line 1459

Of course I cleared the views cache but it didn't help.

It seems that the "block" page is the only page I can't reach. Duplicating and adding new views seems to work fine.

Thanks in advance for your help.

Regards,
Stefan