Unable to create a web experience in ArcGIS Enterprise

Description

Attempts to create a new ArcGIS Experience Builder web experience in an ArcGIS Enterprise environment fails and the following error message is returned:

Error:
Error 400: Invalid Redirect URI

Cause

The ArcGIS Web Adaptor for Portal for ArcGIS is incorrectly configured using the machine hostname instead of the Domain Name System (DNS) alias.

Solution or Workaround

Reconfigure the Web Adaptor to use the DNS alias

1. Unregister the Web Adaptor by following the instructions in ArcGIS Enterprise: Unregister ArcGIS Web Adaptor.
2. Register the Web Adaptor with Portal for ArcGIS using the DNS alias by following the instructions in ArcGIS Enterprise: Configure ArcGIS Web Adaptor from the configuration web page.