"An unexpected error has occurred" while accessing the Lifecycle Manager

Products

• VMware vCenter Server

Issue/Introduction

• The below message appears up when accessing Lifecycle Manager menu in UI. The rest of the page is blank
  • "An unexpected error has occurred" 
  • You have no privileges to view this object or it does not exist.
• vCenter is in ELM with one or more vCenters
• The following is noted in /var/log/vmware/vsphere-ui/logs/vsphere_client_virgo.log:
  • [YYYY-MM-DDT##:##:##.###+0#:00] [WARN ]-nio-127.0.0.1-5090-exec-253 com.vmware.vum.client.remoting.impl.VumServiceImpl  Request failed com.vmware.vim.vmomi.client.exception.SslException:javax.net.ssl.SSLException: SSL handshake from 0.0.0.0/0.0.0.0:36504 to <ELM_VC_FQDN>/<ELM_VC_IP>:8084 failed in 15 ms
• /var/log/vmware/vsphere-ui/logs/catalina.****-**-**.log:
  • Caused by: com.vmware.vim.vmomi.client.exception.ConnectionException: https://ELM_VC_FQDN:8084/vci/sdk invocation failed with "org.apache.http.conn.ConnectTimeoutException: Connect to ELM_VC_FQDN:8084 [ELM_VC_FQDN/ELM_VC_IP] failed: connect timed out"

Environment

vCenter Server

Cause

Port 8084 isn't fully accessible between each vCenter in ELM

Resolution

• TCP port 8084 is a required port in Enhanced Linked Mode (ELM) environments, used by vSphere Lifecycle Manager to facilitate information exchange between vCenter Server nodes.
  • Refer - Ports Required
• For each vCenter in ELM; ensure each other vCenter is accessible over port 8084 - including SSL traffic.
• To check that the connection is clear on both open port and SSL traffic, run the below commands from vCenter SSH between both the vCenters which are in ELM:
  • openssl s_client -connect <ELM_VC_FQDN>:8084
  • curl -v telnet://<Destination-vCenter-IP>:8084

Example good output:

CONNECTED(00000003)
depth=1 CN = CA, DC = vsphere, DC = local, C = US, ST = California, O =<VC FQDN>, OU = VMware Engineering
verify return:1
depth=0 CN = <VC FQDN>, C = US
verify return:1
---
Certificate chain
 0 s:CN = <VC FQDN>, C = US
   i:CN = CA, DC = vsphere, DC = local, C = US, ST = California, O = <VC FQDN>, OU = VMware Engineering
   a:PKEY: rsaEncryption, 3072 (bit); sigalg: RSA-SHA256
   v:NotBefore: MONTH DATE HH:MM:SS YYYY GMT; NotAfter: MONTH DATE HH:MM:SS YYYY GMT
---
Server certificate
-----BEGIN CERTIFICATE-----
<raw_certificate_string>
-----END CERTIFICATE-----