I agree with @dmkizer. The same thing is happening to me. The login page returns me to my homepage after logging in, not the dashboard.
Upon commenting out the below line in my .htaccess, I was able to log into my dashboard normally (though wp-admin; though, the functionality of the plugin doesn’t work anymore – of course).
# RewriteRule ^youcanttouchthis/?$ /wp-login.php [QSA,L]