If you’ve just updated your vCSA to version 7 like me, you may find an issue with vSphere update planner, one of the new functionalities.
This simply does not appear :

To solve the issue, check the file :
/etc/vmware-rhttpproxy/endpoints.conf.d/ui-plugins.conf
it should contain a line like :
/plugins/com.vmware.lcm.client~1.0.0.0~1664750149/<FQDN>443 remotessl <FQDN>:443/ reject allow <THUMBPRINT>
That was not the case on my vCSA. If it’s not, add it manually.

Then restart the vSphere UI service
service-control --restart vsphere-ui
go back to the HTML 5, the update planner should now be available :
