Do not fear, the fix is simple ish.
- gather together your esxi thumbprints. There's probably a one-liner that could do this, I found this 2012 virtuallyghetto link that'll hook it together: lamw saves the day again
- ~> cd /usr/lib/vmware-vcli/apps/general
- ~> ./credstore_admin.pl add --server <server name in vifp> --thumbprint <thumbprint>
So your next step can be to run credstore_admin.pl against all the ESXi hosts you have OR you can manually edit the vicredentials.xml file with all the info. Your choice. Use William's option 3 to gather the thumbprints and just add the credstore command to the for loop. Easy peasy.
If I was really smart I'd update /opt/vmware/vma/samples/perl/bulkAddServers.pl to get the thumbprint. Looks like it doesn't enter it...