Some things to look at:
1. There are DNS forward and reverse records referring to the alias.
2. The alias is listed on the new certificate as one of the DNS entries under the Subject Alternative Name.
3. The /etc/vmware/vsphere-ui/webclient.properties file has the alias whitelisted and the following section is not commented out:
sso.serviceprovider.alias.whitelist=<aliasFQDN>
Where <aliasFQDN> is the alias that is used for the vCenter without the <> marks.
4. Check the ownership of the webclient.properties file. It should be owned by vsphere-ui. If it is owned by root, the vSphere client will not load.
service-control --stop vsphere-ui
cd /etc/vmware/vsphere-ui/
cp webclient.properties /var/tmp/webclient.properties.bak
vi webclient.properties
wq!
V. Start the vSphere client service.
service-control --start vsphere-ui
4. Run the command: "chown --reference=compatibility-matrix.xml webclient.properties"
as the compatibility-matrix.xml is owned by the vsphere-ui account.
This issue is being checked by Diagnostics for VMware Cloud Foundation.
The check is as follows: