Looks like a bug to me, in packages/vbcms/widget/execphp.php. In function getPageView() the first line is
PHP Code:
$config = $this->widget->getConfig();
but the line that loads the widget doesn't get called until later:
PHP Code:
$this->assertWidget();
so you could try moving the assertWidget() line to the beginning of that function, or in your code you could add a call to $widget->getConfigView() before the call to getPageView().