Got notice when i've done register.
Showing "Cookie error. Try again. (If you just registered: it worked, just login.)"
its fine and its happen to all of us after registering a new account. all you gotta do is just login normally and it should work like charm.
and i also suggest enabling your cookies and javascript on your browser settings just to avoid any errors or login problems. clearing your browsers cache and history is also fine and a better idea if your facing a slow loading of the page.