Hi,
i get a Fatal Error:

“Fatal error: Call to undefined method stdClass::in_admin() … on line 644”

If i want to open the admin columns area. Other plugins are working fine!

This functions seems to be involved:

function is_admin() {
if ( isset( $GLOBALS['current_screen'] ) )
return $GLOBALS['current_screen']->in_admin();
elseif ( defined( 'WP_ADMIN' ) )
return WP_ADMIN;
return false;
}

Seems to be the same problem as this 2 years ago: “https://wordpress.org/support/topic/fatal-error-with-wp35”

Regards,