Hi
I am getting a strange problem
Whenever I login, I get redirected to a blank page with the browser url as

http://www.mysite.com/index.php?main...action=process

When I click Refresh, nothing happens(same blank page)
But when I click on Back in browser, I see the 'My Account', 'Log Off' etc links indicating that I have logged in the site
Same is the case with 'Log Off' and Create Account
Can someone tell me whats happening
I tried to debug the file
/public_html/includes/modules/pages/login/header_php.php
and came to know that the problem is here
zen_redirect(zen_href_link(FILENAME_DEFAULT, '', $request_type));
Also, tried using
Code:
zen_redirect("www.google.com") 
//or
header('Location: ' . 'www.google.com');
for testing but nothing seems to work

Can someone please help me?
I already went through this link
https://www.zen-cart.com/tutorials/index.php?article=82