I have 2 vCenters and I'm unable to register to either one. We have a local user, root, defined in SSO, and all I get is "Failed to register plugin.". No reason why is given. I've read the FAQ and it says that domain accounts aren't supported but this one isn't. The root account is a member of the Adminstrator Role.
What's the catch? Are there other log messages available as to why it won't register?