issue #18931 fixed.

Author: ayaz

app/code/Magento/Catalog/i18n/en_US.csv

@@ -808,4 +808,5 @@ Details,Details
 "Product Name or SKU", "Product Name or SKU"
 "Start typing to find products", "Start typing to find products"
 "Product with ID: (%1) doesn't exist", "Product with ID: (%1) doesn't exist"
-"Category with ID: (%1) doesn't exist", "Category with ID: (%1) doesn't exist"
+"Category with ID: (%1) doesn't exist", "Category with ID: (%1) doesn't exist"
+"You added product %1 to the <a href=""%2"">comparison list</a>.","You added product %1 to the <a href=""%2"">comparison list</a>."

app/code/Magento/Checkout/i18n/en_US.csv

@@ -182,3 +182,4 @@ Payment,Payment
 "Items in Cart","Items in Cart"
 "Close","Close"
 "Show Cross-sell Items in the Shopping Cart","Show Cross-sell Items in the Shopping Cart"
+"You added %1 to your <a href=""%2"">shopping cart</a>.","You added %1 to your <a href=""%2"">shopping cart</a>."