I've been working hard on upgrading our drupal 6 site to drupal 7. Have been following steps in upgrade.txt; and am working on my second practice site. With core at 6.38 and all my contrib modules updated, when I run update.php, with the latest 7.x core I get this error:
PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 's.ssid' in 'where clause': SELECT u.*, s.* FROM {users} u INNER JOIN {sessions} s ON s.uid = s.uid WHERE s.ssid = :ssid;Array([:ssid] => TPQlk-gobbledygookXyZ34gbgh) in _drupal_session_read() (line 92 of /home/examplesite/includes/sessions.inc).
Tried twice putting together everything needed and got this same error twice. Not sure where to look next. One area that is not clear to me is the exact content of sites/all/modules at this point, when everything is updated¤t in 6.* and you disable all the contrib modules and get a home folder set up with D7 core, and the few needed files - and ready to run update. I wonder if I can better succeed if there is no contrib module code& files hanging around in sites/all/modules? The sentence in Upgrade.txt that says " Leave other modules in place, even though
they are incompatible with Drupal 7.x." confuses me. Should I get all 6.x contrib modules out of sites/all/modules? And for modules like CCK where they are mostly in core, when I got to run update on 7.43 core, should a 7.x version of CCK be in place, or the old 6.x version, or nothing? I have read the documentation a hundred times and I find it ambiguous. Or is this just a database issue?
Any insight into what derailed update would be appreciated.