I've been with this problem now for few days. I recently installed and configured Oracle BI 12c to use Ms-Active directory as Authenticator. I've managed to configure LDAPs [Active Dir Over SSL] and I'm able to See all MSAD users and groups in Weblogic Console.
I can use the AD user to login in both Weblogic console and FMW Control. But when I try to use the same user to LogIn to OBI analytics/VA it gives me "The specified credentials could not be authenticated" error and blocks it. The default user "Weblogic" logs in fine in all. I'm using OBIEE 12.2.1.3.0. Any Help is appreciated.
Did you add the virtualize=true parameter and set both security providers to sufficient?