Can not add module and edit page in dotnetnuke 7.10 after upgrade-Collection of common programming errors

After I upgrade my dot net nuke version from 6.01 to 7.10 ,all things are working find but after admin login can not use some functionality like page edit,add new module.All the times it throws same error

System.Exception: Unhandled Error: —> System.ArgumentException: Item has already been added. Key in dictionary: ‘UserInfo’ Key being added: ‘UserInfo’ at System.Web.Http.WebHost.HttpControllerHandler.EndProcessRequest(IAsyncResult result) at System.Web.HttpApplication.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) — End of inner exception stack trace —

Please help me …Thanks