Can't get passed the Login Popup

I’ve followed your instructions for the installation and everything looks correct. When I goto mydomain/sitecake.php the login popup appears and I type “admin” and the spinny wheel spins forever. I notice that sitecake has added folders to my server so it is definitely working on that end. However, i can never get past the login window. When I close the login window and refresh the page to try again I get the “Admin already logged in” message. I’ve tried changing the password and again the spinny wheel spins forever and I never get passed the login popup. It also doesn’t change the password.
Anyone else have a similar issue and know how to fix?
Thanks for your help!

What does the php error log say?

This is from my PHP log:

PHP Warning: mkdir(): Permission denied in /hermes/bosnaweb08a/b1545/ipg.erinmaguirecom/sitecake/2.2.10/server/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Session/Storage/Handler/NativeFileSessionHandler.php on line 52

I went to line 52 of that file and it states:
if ($baseDir && !is_dir($baseDir)) {
mkdir($baseDir, 0777, true);

If I make my base directory fully writable and executable, doesn’t that leave the server vulnerable?

Sitecake is using the Silex’s default SessionServiceProvider (Silex\Provider\SessionServiceProvider) which, in turn, is using the Simphony’s default NativeFileSessionHandler.
NativeFileSessionHandler is using ini_get(‘session.save_path’) to determine the path for storing session files. The line 52 is executed only if the path does not exist or is not accessible by PHP.
Check your hosting environment for ‘session.save_path’ (e.g. using phpinfo()). You could also set a new value by defining the following in Sitecake’s config.php (sitecake/2.2.10/server/config.php):

$app['session.storage.save_path'] = 'a path/directory for storing session files'

or, setting directly session.save_path:

ini_set('session.save_path', 'a path/directory for storing session files');