System.ServiceModel.Security.SecurityAccessDeniedException

please give assistance to this issue

I am getting this error multiple time..

Object reference not set to an instance of an object.

1. when I want to login with paticular  user 

2.when I am creating a page

3.when I am creating a wepart page

4.i cant view site settings , i have to go manualy from url

5.when i want to make any changes it is showing same object reference not set to an instant of an object.

6.I try to start user profile syn service with the farm account administrator. but it is still showing starting.

7.when i try to open a web part page it is saying below error

System.ServiceModel.Security.SecurityAccessDeniedException

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: Microsoft.Office.Server.UserProfiles.UserProfileApplicationNotAvailableException: System.ServiceModel.Security.SecurityAccessDeniedException

Source Error: