Kinda old thread but its the exact same problem i have, i moved the site to a new server, i changed all the config files, and i moved the database.
On the new server i can se the site when i go to mydomain.com but when i go to mydomain.com/manager the same error as mentioned above comes.
I did an upgrade and ran the setup and everything was OK in the setup, but i still get the error.
I followed your guide and still got the same problem, i have tried like 10 times now with new transfers and now im out of ideas :S the site is
http://jcbrandtatning.se.preview.binero.se/ and the site works but the manager wont work, any ideas?