A new KB article was posted today to the address issue where Virtualization Manager 6.1.1 fails to connect to vCenter after being upgraded from version 4.0 or below. The issue is caused by the RSA key size constraint added in the java version that shipped with Virtualization Manager 6.1.1 requiring that the RSA key size to be at least 1024 Bits. The knowledge base article has the fix to get your Virtualization Manager data collections from vCenter up and running again.
To access the KB article click here
Thank you for this, I was able to configure my new Virtualization Manager install after I found this. After an upgrade from VMware 4.1 to 5.0U3, my certificate was 512 bits, and being rejected. My google search brought me to this page, then on to the resources to resolve the issue. Much appreciated.