PowerProtect Linux File System registration fails with "preferred address is invalid"

The PowerProtect Data Manager is used to protect the Linux Servers with the file system agent (application agent). The application agent registration with the fully qualified domain name (FQDN) or IP fails with "preferred address is invalid."

[root@my-application-agent]# /opt/dpsapps/agentsvc/register.sh --enable
AgentService is already commissioned.
Enter the PowerProtect Data Manager server FQDN or IP address: my-ppdm.my-domain.com
The PowerProtect Data Manager server FQDN or IP address that is used by the application agent host is my-ppdm.my-domain.com
To use the Fully Qualified Domain Name (FQDN) as the preferred address for the agent host, in the PowerProtect Data Manager UI, go to Infrastructure > Application Agents and select Configure DNS Name Resolution.
Enter the preferred FQDN or IP address of the application host: my-application-agent.my-domain.com
preferred address is invalid
Enter the preferred FQDN or IP address of the application host: XXX.XXX.XXX.XXX
preferred address is invalid
Failed to get a valid preferred address of the application host even after 2 attempts. Failing registration

The name resolution between the application agent and PowerProtect Data Manager is working properly. The PowerProtect Data Manager Application Agents page shows a registration with the application agent IP address and localhost.localdomain.

The application agents /etc/hosts file contains a 127.0.0.1 loopback entry for localhost.localdomain. The localhost.localdomain is causing the application agent configuration to use the incorrect name during the registration.

[root@my-application-agent]# cat /etc/hosts
127.0.0.1	localhost.localdomain locoalhost
::1		localhost.localdomain locoalhost
XXX.XXX.XXX.XXX my-application-agent.my-domain.com my-application-agent

The application agents /etc/hosts file lines for localhost.localdomain should be commented or updated to reflect the application agents name.

[root@my-application-agent]# cat /etc/hosts
#127.0.0.1	localhost.localdomain locoalhost
#::1		localhost.localdomain locoalhost
XXX.XXX.XXX.XXX my-application-agent.my-domain.com my-application-agent

or

[root@my-application-agent]# cat /etc/hosts
XXX.XXX.XXX.XXX my-application-agent.my-domain.com my-application-agent
127.0.0.1	my-application-agent.my-domain.com my-application-agent
::1		my-application-agent.my-domain.com my-application-agent