Adding ESXi to vCenter inventory fails with "Unable to connect because the username or password is incorrect" after stuck at 80 percent

Products

• VMware vCenter Server

Issue/Introduction

• Unable to add/re-add ESX Host to vCenter inventory as the process fails at 80 percent
• An error message is seen, stating:
  
  Error: Unable to connect because the username or password is incorrect
  
  
• License updates may have been performed prior to this changing from evaluation.
• /var/log/vmware/vpxd/vpxd.log in the vCenter Server contains messages simular to:

  ####-##-##T##:##:##.###Z warning vpxd[#####] [Originator@#### sub=TrustedInfrastructure.HostConfig opID=########-#####-auto-###-##:########-##] [CreateOrUpdate] Policy with local user name vpxuser already exists on host <ESX_IP>. Exception: N4Vpxd7Clients22AlreadyExistsExceptionE(Error:
  -->  com.vmware.vapi.std.errors.already_exists
  -->  No messages!
  -->  )

• ESX Host has no Hostname/FQDN configured.
• There is no hostname/FQDN to IP address translation configured in the /etc/hosts file in the vCenter Server Appliance operating system either. Contents will look similar to below:

  # Do not modify this file directly, please use esxcli.
  # Any line beginning with a pound sign is a comment and will not be read.
  127.0.0.1 localhost.localdomain localhost
  ::1            localhost.localdomain localhost

Environment

• VMware vCenter Server 8.0.x
• VMware vSphere ESXi 8.0.x

Cause

This issue occurs when there is no valid hostname configured for the ESXi host.

Resolution

To fix this issue, take the following steps:

• Update the ESXi to have a valid Hostname/FQDN and update DNS by implementing the recommendations outlined inHow to change ESXi host name, FQDN and DNS server IP
• Retry adding the ESXi to vCenter inventory.

Additional Information

Modifying host entry in /etc/hosts file for vCenter or ESXi host using vi editor