Fix entity insert with array fields.

src/Entity.php

@@ -541,6 +541,10 @@ abstract class Entity
 			// Prepend property name by the prefix.
 			$propertyName = $prefix.$propertyName;
 
+			if (!($propertyDefinition instanceof FieldBlueprint))
+				// Ignore all properties that are not normal fields.
+				continue;
+
 			if (isset($this->$propertyName))
 			{ // If property is set, converting it.
 				// Get property type.