Just finished upgrading a site from EE 1.7.1 to 2.5.2. Site is originally quite old (pMachine), and ran into the large database error during the upgrade requiring me to manually run the script it created. That aside, the upgrade seemed to run correctly.
Now when I try to login to the control panel it simply refreshes the login, no error, even though I’m using a known good login. I’ve tried clearing my cookies, as several have suggested, and using different browsers, to no change in effect.
Any suggestions?