This issue pertains to the RAF EUI as well as the RAF 3.0.1 Web UI when connection to LDAP and AD.
Fixpack 18.104.22.168 will contain the fix for this issue.
A work around, is to create local RAF users until the fixpack has be released. If you have additional questions on how to do this. Please see the link below.
Common error message noted in the logs:
WARNING: Login failed - no domain specified