Accessing Lifecycle Manger or the ESXi Host Update tab shows the error "An unexpected error occured. Unauthorized"

Products

• VMware vCenter Server

Issue/Introduction

• Lifecycle Manager is not accessible in the vSphere client and accessing it will show the following error message:
  "An unexpected error has occurred"
  
• Accessing baselines from the ESXi host will show the following error message:
  "An unexpected error has occurred"
• The vCenter logs shows errors similar to the following, with the New and Old thumbprint conflicting:
  
  /var/log/vmware/vmware-updatemgr/vum-server/vmware-vum-server.log
  yyyy-mm-ddThh:mm:ss.Z warning vmware-vum-server[xxxxx] [Originator@6876 sub=IO.Connection] Failed to SSL handshake; SSL(<io_obj p:0x0000000000000000, h:49, <TCP '127.0.0.1 : 40834'>, <TCP '127.0.0.1 : 443'>>), 
e: ###########(certificate verify failed (SSL ROUTINES)), duration: 20msec
yyyy-mm-ddThh:mm:ss.Z warning vmware-vum-server[xxxxx] [Originator@6876 sub=HttpConnectionPool-000000] Failed to get pooled connection; <cs p:0000000000000000, TCP:<VC_FQDN>:443>>, 
SSL(<io_obj p:0x0000000000000000, h:49, <TCP '127.0.0.1 : 40834'>, <TCP '127.0.0.1 : 443'>>), duration: 54msec, N7Vmacore3Ssl18SSLVerifyExceptionE(SSL Exception: Verification parameters:
--> PeerThumbprint: ##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##      <==== This Thumbprint should match the Custom Machine SSL certificate
--> ExpectedThumbprint: ##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##:##     <==== This Thumbprint will be the old vCenter Machine SSL certificate
--> ExpectedPeerName: <VC_FQDN>
  --> The remote host certificate has these problems:
  -->
  --> * self-signed certificate in chain)

Environment

VMware vCenter Server 8.x

Cause

Updating the Machine SSL certificate via the vSphere Client restarts only specific services. 
The Lifecycle manager services are excluded from this automatic restart, preventing the certificate update from being reflected for this service.

Resolution

Restart the VMware Update Manger Service to reload the certificate in the service:

1. service-control --restart vmware-updatemgr

Once the service is restarted, reloading the UI will populate the Baselines and Images.