Magento – Failed to load the “Magento_GiftMessage/js/view/gift-message” component in magento 2

if that's still relevant, here's the answer:

Magento_SalesRule/js/view/payment/discount requires Magento_Checkout/js/model/quote, which asks for window.checkoutConfig.quoteData on line 32:

quoteData = window.checkoutConfig.quoteData,

window.checkoutConfig is not available anywhere except the checkout page - it is set in module-checkout/.../templates/onepage.phtml on line 26:

window.checkoutConfig = <?= /* @escapeNotVerified */ $block->getSerializedCheckoutConfig() ?>;

So, you are getting a TypeError: Cannot read property 'quoteData' of undefined. After that, url-builder produces the same kind of error when trying to read window.checkoutConfig.storeCode. You can see it if you set a breakpoint in require.js on line 883, where it handles such errors. Look at the stack trace printed in the console and click on the function call right before onError (it says check).

I have faced same issue on cart and checkout page, In console it shows me "Failed to load the component" error. I have research more about this and check with disable all third party modules and theme but no luck.

So, I have checked with comment out app/etc/env.php to env_bck.php file and run URL from browser address bar. I have check "Readiness Check" and found some PHP extension is missing.

I hvae installed missing PHP extension and checked site it is working fine.

This solution might be help.

Thanks.