Fix vSphere Web Client stuck at 'loading page' after entering admin credentials

Products

VMware vCenter Server VMware vSphere ESXi

Issue/Introduction

Post making changes to DNS entries in VAMI unable to access vSphere web client and the page is found stuck at loading.
service-control --status --all shows all the services in running status.
DNS details shows correctly in VAMI but nslookup on vCenter FQDN fails to resolve.
/var/log/vmware/vsphere-ui/logs/vsphere_client_virgo.log:

[yyyy-mm-ddThh:mm:ss] [INFO ] p-nio-127.0.0.1-5090-exec-10 70000124 100020 ###### com.vmware.vsphere.client.security.websso.WebssoUtil [authenticationError] Message details: id=_##############################, type=AUTHN_RESPONSE, source='https://vCenterhostname.domain.com/websso/SAML2/Metadata/vsphere.local', target='https://vCenterhostname.domain.com/ui/saml/websso/sso', issueInstant=''
[yyyy-mm-ddThh:mm:ss] [ERROR] p-nio-127.0.0.1-5090-exec-10 70000124 100020 ###### com.vmware.vsphere.client.security.websso.LogonProcessorImpl Status: urn:oasis:names:tc:SAML:2.0:status:Requester, sub status: null
[yyyy-mm-ddThh:mm:ss] [INFO ] tp-nio-127.0.0.1-5090-exec-2 70000129 100020 ###### com.vmware.vsphere.client.security.util.Util getUserSession called on an inactive session.
[yyyy-mm-ddThh:mm:ss] [WARN ] tp-nio-127.0.0.1-5090-exec-4 com.vmware.vise.vim.fabric.BifrostConfigurer Failed to create app-fabric connection: clientId is null

/var/log/vmware/sso/vmware-identity-sts-default.log:

[yyyy-mm-ddThh:mm:ss] WARN sts-default[23:jaeger.RemoteReporter-QueueProcessor] [CorId= OpId=] [io.jaegertracing.internal.reporters.RemoteReporter] FlushCommand execution failed! Repeated errors of this command will not be logged.
Caused by: java.net.PortUnreachableException: ICMP Port Unreachable
at java.net.PlainDatagramSocketImpl.send(Native Method) ~[?:1.8.0_452]
at java.net.DatagramSocket.send(DatagramSocket.java:693) ~[?:1.8.0_452]
at io.jaegertracing.thrift.internal.reporters.protocols.ThriftUdpTransport.flush(ThriftUdpTransport.java:149) ~[jaeger-thrift-1.8.0.jar:1.8.0]
at org.apache.thrift.TServiceClient.sendBase(TServiceClient.java:73) ~[libthrift-0.14.1.jar:0.14.1]
at org.apache.thrift.TServiceClient.sendBaseOneway(TServiceClient.java:66) ~[libthrift-0.14.1.jar:0.14.1]
at io.jaegertracing.agent.thrift.Agent$Client.send_emitBatch(Agent.java:70) ~[jaeger-thrift-1.8.0.jar:1.8.0]
at io.jaegertracing.agent.thrift.Agent$Client.emitBatch(Agent.java:63) ~[jaeger-thrift-1.8.0.jar:1.8.0]
at io.jaegertracing.thrift.internal.senders.UdpSender.send(UdpSender.java:84) ~[jaeger-thrift-1.8.0.jar:1.8.0]
at io.jaegertracing.thrift.internal.senders.ThriftSender.flush(ThriftSender.java:114) ~[jaeger-thrift-1.8.0.jar:1.8.0]
... 3 more

Environment

VMware vCenter Server
VMware vSphere ESXi

Cause

The DNS changes made in VAMI is not updated in the vCenter appliance configuration file. The underlying network configuration file in the appliance - /etc/resolv.conf still reflects the old DNS server details causing the vCenter appliance being unable to resolve its own FQDN or other critical network-dependent services (like SSO/SAML), resulting in authentication failures and an unresponsive web client.

Resolution

To verify and update the current DNS configuration using the tool - vami_config_net.
- Open a console session of the VCSA, then login with root.
- Run the following command: /opt/vmware/share/vami/vami_config_net

(Command output below)

Main Menu
0) Show Current Configuration (scroll with Shift-PgUp/PgDown)
1) Exit this program
2) Default Gateway
3) Hostname
4) DNS
5) Proxy Server
6) IP Address Allocation for eth0

- Enter option 4 to update the DNS entries.

Additional Information

VMware vCenter Server Appliance hostname and DNS configuration

Update DNS Server IP address for vCenter Server