In vCenter you are seeing the following error: Error downloading plug-in. Make sure that the URL is reachable and the registered thumbprint is correct. (VLSR Appliance FQDN): Name or service not known
vCenter (All versions)
This issue is caused by the vCenter having the incorrect DNS server which does not allow for the proper resolution of the VSLR appliances.
nslookup commands against the VSLR appliance FQDN fails.
Correct the DNS server in the vCenter Server management console.
The information on how to do this can be found in: https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere/8-0/vcenter-server-installation-and-setup-8-0.html