I recently migrated over to a new server, first doing a clean install 11g XE, then using a FULL DB import which contained a previously upgraded APEX 4.2 in the DMP file. I verified that the schema APEX_040200 was imported, however the older version of APEX is starting up when I launch APEX from the browser. I tried running the script "APEXINS.SQL" but it complains that the schema APEX_040200 already exists.
Do I just need to drop the schema APEX_040200 first, then execute the upgrade script, or will that screw things up?
First thing you should realize is: this is a Database thing, not an APEX thing.
For your question, I'm going to guess 'yes'. DROP APEX_040200 CASCADE;
I'd also hunt down the uninstall script for the default version and run that.
BTW - 99% of the time, the 'correct way' to move a database from one server to another is to use your Backups.
And exp/imp files ARE NOT backups.
Using your backups does two things:
makes it easier on you because you'll never run into this kind of conflict.
proves that your backups and recovery process works.