I just upgradet my site to 5.5.2.1 from the dashboard and first it didn't work at all, I just got an error when I went to the page and the same error came up when I tried to login. With help from another forum discussion:

http://www.concrete5.org/community/forums/jobs1/client-updated-his-...

I got the site running again, and everything seems to be fine but when I login I get no menu at the top, the site just looks like the frontend, I can't edit anything!

Does anyone know what to do?