Found the issue!!
I was following the upgrade instructions so carefully I didn't notice that when I went to WWW.mydomain.com/adserver_new, it actually automatically redirected to the non WWW url http://mydomain/adserver_new.....
but my conf file was named www.mydomain...... and was thus being ignored. As soon as I removed the "www" from the beginning of my conf file the upgrade screen came up instead of the install screen.
Why does the install redirect automatically to the non WWW version ???????
This drove me insane for weeks!
But now when I click agree on the first screen, I get a 500 Internal error.
Steps I did:
1: upload revive 3.0.2 to a new folder called "adserver_new"
2: made a copy of the openx database.
3: downloaded the openx conf.php file edited it in notepad with the new copied database connection details (dbname,user,password).
4: uploaded the edited conf.php file to adserver_new/var
5: browsed to folder "adserver_new" got the upgrade screen. Clicked "I agree" . get to "http://mydomain.com/adserver_new/www/admin/install.php?action=check" with "500 Internal Server Error".
What did I do wrong?