Message from Perforce Visual Client - client 'yourclient' has no root usable from host 'yourhost'

Public service announcement!

Since Googling has helped me not at all with this one, I'll report on my findings. I think I know what it means. You get it if you log into Perforce, browse for a workspace, and then pick a workspace from a different machine than you're currently on. You might need to create your own workspace. And it's a good sign, because at least it means you've succesfully connected to the server. Much better than the 'partner exited unexpectedly' or 'unable to create workspace' messages, which probably mean you're not connected at all.