Windows 2016 Internet Information Services (IIS) does not serve the default web page documents after ArcGIS Web Adaptor is installed on Microsoft Azure Esri ArcGIS Enterprise 10.6 Machine Image Templates
This is a known issue.
We are following up with Microsoft on enabling .Net Framework 4.6 in Azure Server 2016 machines with ARR.
解决办法
The issue can be manually resolved by uninstalling the web adaptor, removing all Internet Information Services (IIS) components from the machine, renaming the inetpub folder, and installing the ArcGIS Web Adaptor when no IIS components are configured on the machine. The web adaptor and default documents then works successfully.