After installing the transaction service for Sitecore Commerce powered by Microsoft Dynamics and browsing to any of the services (for example, /TransactionService/ShoppingCartService.svc), the following error may occur:
HTTP Error 404.3 - Not Found
To resolve the issue, modify the Windows features for your versions of the .NET framework and enable HTTP Activation. For example, for Windows 10 and the 3.5 and 4.6 versions of the .NET Framework: