Hi Sridhar,
The following may also be related:
1. OS user "SSDADM" is in the Administrators group of the PAS server.
2. The password of "SSDADM" is valid and it doesn't require to change the password at the next logon.
3. If some special characters existing in its password, try if changing the password and removing the special characters could resolve the issue or not.
4. Check the properties of the service "SAP SM Listener" and make sure "Allow service to interact with desktop" on the Log On tab is checked.
Regards,
Alicia