Can not login admin site

@stupidpro,

What other errors are you seeing?

Hi @php_rocs,
not any errors display

I checked session with:
<?php
if (isset($_COOKIE["PHPSESSID"])) {
    echo "active";
} else {
    echo "don't see one";
}
?>
it run OK, but

I think session not working at my site, I go to phpmyadmin set new user
step 1: not active new user, go back page login and have received message " the acount block"
step 2: go phpmyadmin active account, then login again and have message "the password wrong"

@stupidpro,

Have you verified that your database connection works properly? Are you point to the same database or a different database?