Unable to open Siebel Tools after fresh Install of IP2015

Hi Team,

We have installed Siebel Tools IP2015 and after installing I configured Server Data Source. I checked in ODBC Connection and able to make a connection but when I open Siebel Tools,

I get below error message

An internal error has occurred within the authentication subsystem for the Siebel application. Please contact your system administrator for assistance.(SBL-DAT-00565)

Siebel Tools Log shows below error message :-

2021 2016-02-18 17:26:40 2016-02-18 17:26:44 +1100 00000006 001 003f 0001 09 siebdev 47732 13108 C:\Siebel\15.0.0.0.0\Tools\log\siebdev(008).log 15.0.0.0 [23048] ENU

GenericLog GenericError 1 0000000256c5ba74:0 2016-02-18 17:26:40 (secmgr.cpp (2768) err=4597538 sys=127) SBL-SEC-10018: Can't load sscdo90.dll(SBL-GEN-02500)

GenericLog GenericError 1 0000000256c5ba74:0 2016-02-18 17:26:40 (secmgr.cpp (2840) err=4597521 sys=0) SBL-SEC-10001: An internal error has occurred within the authentication subsystem for the Siebel application. Please contact your system administrator for assistance.