V8.3.2: Log shows this error for a particular page (other pages behave ok):

Exception Occurred: /var/www/..../concrete/src/Form/Service/Widget/ExpressEntrySelector.php:13 Argument 1 passed to Concrete\Core\Form\Service\Widget\ExpressEntrySelector::selectEntry() must be an instance of Concrete\Core\Entity\Express\Entity, null given, called in /var/www/..../concrete/attributes/express/form.php on line 3 (0)

Apache is returning a 500 forhttps://..../ccm/system/panels/details/page/attributes?cID=187... when clicking attributues in the design side panel or selecting attributes in the sitemap page popup menu

No idea what's causing it, would seem to be a bug?

EDIT: Just upgraded dev site version from 8.2.1 to 8.3.2 with same issue.