I run the install wizard for update manager and the page that takes your server ip, port #, username, password, etc won't accept my credentials. A popup says "Setup failed with an unknown error. vCenter Server credentials could not be validated. I'm using the admin@System-Domain user and it works just fine getting into the vSphere client. I tried Knowledge Base article ID (2000321) but there are no spaces in the paths. Anyone run into this already?
