KB44755 recommends Enabling Unauthenticated Request option.
KB44784 Lists the target URI's for blocking, if you have SSL Inspection in front of the units.
Q - Is there a way to search for the URIs with log filtering on the unit?
(That would aid in knowing if we are having hits and we could block those IPs)
^/+dana/+meeting
^/+dana/+fb/+smb
^/+dana-cached/+fb/+smb
^/+dana-ws/+namedusers
^/+dana-ws/+metric