OCP 4.6 installation fails with error "failed to upload - Service Unavailable"

Issue

• The installation of Red Hat OpenShift Container Platform (OCP) 4.6 fails with the following error message:

time="2020-11-19T09:46:57+01:00" level=debug msg="vsphere_tag.tag: Creating..." 
time="2020-11-19T09:46:58+01:00" level=debug msg="vsphere_tag.tag: Creation complete after 0s [id=urn:vmomi:InventoryServiceTag:494d7540-c8a5-4d60-9c7d-7530380078dc:GLOBAL]" 
time="2020-11-19T09:46:58+01:00" level=debug msg="vsphere_folder.folder[0]: Creating..." 
time="2020-11-19T09:46:58+01:00" level=debug msg="vsphere_folder.folder[0]: Creation complete after 0s [id=group-v263]" 
time="2020-11-19T09:46:58+01:00" level=debug msg="vsphereprivate_import_ova.import: Creating..." 
time="2020-11-19T09:46:59+01:00" level=error 
time="2020-11-19T09:46:59+01:00" level=error msg="Error: failed to upload: Post \"https://esx01.example.com/nfc/52cc393f-eb31-0823-4e9d-d5eae04743de/disk-0.vmdk\": Service Unavailable" 
time="2020-11-19T09:46:59+01:00" level=error 
time="2020-11-19T09:46:59+01:00" level=error msg="  on ../../tmp/openshift-install-679543663/main.tf line 43, in resource \"vsphereprivate_import_ova\" \"import\":" 
time="2020-11-19T09:46:59+01:00" level=error msg="  43: resource \"vsphereprivate_import_ova\" \"import\" {" 
time="2020-11-19T09:46:59+01:00" level=error 
time="2020-11-19T09:46:59+01:00" level=error 
time="2020-11-19T09:46:59+01:00" level=fatal msg="failed to fetch Cluster: failed to generate asset \"Cluster\": failed to create cluster: failed to apply Terraform: failed to complete the change" 

• The step vsphereprivate_import_ova fails when trying to install OpenShift Container Platform on vSphere.