ArcGIS Enterprise AWS CloudFormation deploy fails with error: "Unable to connect to WebAdaptor URL : https://[IP ADDRESS]/portal/webadaptor

Description

When attempting to deploy an AWS CloudFormation template, the deploy fails. The logs throw the following errors:

ERROR: Failed to configure Web Adaptor with Portal for ArcGIS. Expected process to exit with [0], but received '1'

---- Begin output of "java" -jar "/arcgis/webadaptor10.8/java/tools/arcgis-wareg.jar" -m portal -w 'https://[IP ADDRESS]/portal/webadaptor' -g 'https://[IP ADDRESS]:7443' -u 'admin' -p '[PASSWORD]' ----

STDOUT: Unable to connect to WebAdaptor URL : https://[IP ADDRESS]/portal/webadaptor

This error occurs despite all required ArcGIS Enterprise ports being opened, and has been observed on the Single-machine deployment template for Ubuntu Linux, but is applicable to any template or supported OS.

Cause

The Primary Site Administrator password specified during setup contains disallowed characters, such as underscores. 

The Amazon CloudFormation deploy wizard does not perform validation checking on the supplied Primary Site Administrator password, opening up the opportunity for the user to supply an incompatible password, which causes the deploy to fail when the script attempts to register the Portal Web Adaptor.

Solution or Workaround

Supply a new password that meets the requirements specified in the Portal for ArcGIS PSA documentation and deploy again.