Login problem for sellers

Hello,

Some problem with the Login code from Estatik:
I write credentials on my login page, and it refresh and stay on the same page.
After this, I clic on the login again, and it redirect me to the dashboard.
But, on the dashboard, nothing appear: empty.
I clic refresh, and It comes.

I can’t find any solution for 4 days…

Any help ? Ideas ?

The page I need help with: [log in to see the link]