After upgrade Magento to 2.3.1, Configurable product is not displaying

Question

We have upgraded our Magento site to Latest Magento version Magento 2.3.1, After upgrade, We are facing error while opening configurable product as below.

{
    "[data-role=swatch-options]": {
        "Magento_Swatches/js/swatch-renderer": {
            "jsonConfig": <br /> 
<b>Fatal error</b>:  Uncaught Error: Call to a member function getUrl() on null in /vendor/magento/module-configurable-product/Helper/Data.php:56
Stack trace: #0 /vendor/magento/module-configurable-product/Block/Product/View/Type/Configurable.php(261): Magento\ConfigurableProduct\Helper\Data-&gt;getGalleryImages(Object(Magento\Catalog\Model\Product\Interceptor))
#1 /vendor/magento/module-configurable-product/Block/Product/View/Type/Configurable.php(238): Magento\ConfigurableProduct\Block\Product\View\Type\Configurable-&gt;getOptionImages()
#2 /generated/code/Magento/Swatches/Block/Product/Renderer/Configurable/Interceptor.php(206): Magento\ConfigurableProduct\Block\Product\View\Type\Configurable-&gt;getJsonConfig()
#3 /vendor/magento/module-swatches/view/frontend/templates/product/view/renderer.phtml(16): Magento\Swatches\Block\Product\Renderer\Configurable\Interceptor-&gt;getJsonConfig()
#4 /v in <b>/vendor/magento/module-configurable-product/Helper/Data.php</b> on line <b>56</b><br />

Simple product details page is working fine, but having error in configurable product. Does anybody has solution of this issue? Please help. Thank you.

Answer 1

I have fixed this issue by my own. I have overridden the

\Magento\ConfigurableProduct\Helper\Data

Class in my custom module and forgot to call parent constructor in my Data helper file. So I have added below line of code in file and fixed the issue.

parent::__construct($imageHelper, $urlBuilder);

Thank you.