Cannot use a leading .. to exit above the top directory.

Hello All,

We are facing some issue after login. I have a website https://www.domainname.com which has login. When we keyin the login name and password and clicks on login button, it should redirects to some page.

Our problem is when we click on login button it gives the exception

"Cannot use a leading .. to exit above the top directory."

The above issue doesnt come when we login from SignIn page. 

Can someone please help us.

Thanks in advance.