Query Cart returns internal server error if configurable product was added

Author: XxXgeoXxX

app/code/Magento/QuoteGraphQl/etc/di.xml

@@ -12,6 +12,7 @@
             <argument name="supportedTypes" xsi:type="array">
                 <item name="simple" xsi:type="string">SimpleCartItem</item>
                 <item name="virtual" xsi:type="string">VirtualCartItem</item>
+                <item name="configurable" xsi:type="string">ConfigurableCartItem</item>
             </argument>
         </arguments>
     </type>