Custom Role does not have access to dashboard

You have to give the capability a true or false, like this:

add_role('user', 'User', array( 'read' => true ));

To fix it, first remove the role and than re-add it again.

remove_role('user');
add_role('user', 'User', array('read' => true));

http://codex.wordpress.org/Function_Reference/add_role