Hi Shiva,
On the logs I see the below
ERROR 2016-09-07 05:00:27,855 [http-nio-80-exec-98] ppm.rest (clarity:unknown:195391778__C99897C2-12EE-4598-901A-196FEFB95EF8:PPM_REST_API) AuthenticationFilter :: Exception while authentication user.
com.niku.union.security.SecurityException: Authentication Failure Error!
Below are the things to check
1. Ensure Disable REST API Access is not checked
2. CSK is installed
Regards
Suman Pramanik