Trying to install the High Sierra Public Beta and I get this:
"The installer information on the recovery server is damaged."
I'm booting my MB off an external USB 3 drive. That drive is the cloned drive of a 2017 iMac and worked fine to boot up my 2017 iMac, 2010 iMac, and 2017 MacBook.
EDIT:
Machine hadn't been registered for the beta. Registered and now it works.