A couple of days ago I upgraded from 2.2.1 (IIRC) to 2.5.2. My site broke immediately, and turning on debug mode, I found that I was getting a MySQL error, complaining that exp_members.remember_me didn’t exist. A quick review of the upgrade scripts revealed that the column had been eliminated in favor of an exp_remember_me table. As an immediate fix, I created exp_members.remember_me, where ExpressionEngine is now happily storing what I assume is a session identifier.
Where in Expression Engine were calls to exp_members.remember_me replaced with calls to exp_remember_me? I want to fix this properly, in part because I don’t want to have the same problem with my next upgrade, and in part because I’m hoping that the solution will help to reveal the cause behind a much bigger post-upgrade problem. If I know where this upgrade script failed, then I’ll know where to start investigating.