In log4j.xml file, increase logging level to "DEBUG".<br />e.g. in JBoss\server\all\conf\log4j.xml file,<br />for <Appender name="FILE".., change the threshold level from "INFO" -> "DEBUG".<br />e.g.<br />--<br /><param name="Threshold" value="DEBUG"/><br />--<br /><br />Once that is done, server log should provide more details regarding the authentication failure as specified in the message above. Perhaps it might contain error code from Active Directory. If the lower level message contains AD error code, you might be able to look up that error code on MSDN.