Moved Drupal 6 site to new server - can't login I'm migrating a client's site to a different server because we're changing web hosts. The domain name still points to the old site for now and I either use an ip address or a temporary url to preview the new site. However, since I moved it, I can no longer log in, I get an "access denied" error message. Is this a known issue? How can I resolve it?

EDIT: I oddly don't have this problem when I download the site to my hard drive and run it locally.
This happened to me so many times back in the days of Drupal 6.

99% of the time it was caused by the anonymous user record having been removed from the users table in the database.

Try adding a user to that table with a uid of 0 (and all other fields empty); if the above is what's causing the problem, that should fix it.