I have a bit of a problem there in that I set the admin password but somehow neglected to save the Keepass file! I was planning to try using the instructions that were posted here recently to recover that, once I understand this login issue. Before I lost the password though, attempting to log in as admin produced the same macaroon error.
I am using the correct password for the routergod user. If I purposely use the wrong password I get a more straightforward error message;
ERROR cannot log into controller "openstack": invalid entity name or password
I also created a user for a colleague, indeed that was my first action. At that time I had not attempted to set the admin password. Whatever default token was in place for the admin user was still working at that point. It seems the authorization bit is somehow not working where a password is set.