Find your Google Tag Manager code in your GTM Workspace > Admin tab > click menu Insert Google Tag Manager. Copy the code an insert in to your BigCommerce Stencil template file templates/layout/base.html as showing below:

Add the code below in your Storefront > Footer Script:<style> @media (min-width: 801px) {  .productView-imageCarousel-main-item > a {    position: relative;    display: block;    height: 0;    padding-top: 100%;  }  .productView-imageCarousel-main-item > a img {    position: absolute;    top: 50%;    left: 50%;    transform: translate(-50%, -50%);  } } </style>This code …

Problem happen when BigCommerce change product main image URL recently.To fix this problem, please upgrade all themes to the latest version.If your theme already modified, you can fix this issue manually by editing file templates/components/products/product-view.htmlReplace all string:{{#if ../product.main_image.data '==' this.data}} slick-current{{/if}}By:{{#startsWith this.data ../product.main_image.data}} slick-current{{/startsWith}}If you have any problem, feel free to contact us at&nbs …