Chris G wrote:
I just recently tried to upgrade a Drupal 6.16 installation to the recommended 6.22. It fell in a crumpled heap! I did the upgrade using drush and it produced loads of warning messages about disabled modules because the 'module wasn't compatible with the new version' and also did some database changes which I'm pretty certain was what broke the system completely.
6.16 to 6.22 should be a matter of just doing the upgrade. You might need to disable modules and do the upgrade for them one by one.
I have reverted to 6.16 and restored the database and all is well now, but I'm a bit unsure how to proceed as it feels as if I really should do the security upgrades.
I'm afraid I lost the output from drush where all the warning messages were shown because I just wanted to undo the mess.
I've never used drush. I've always used the GUI. The warning messages though may have been stored in the watchdog table and might could have been viewed from the log report. But that is gone now since you've restored the DB.
I can possibly try again with (yet another) copy of the site and show the error messages here if that might help.
I suggest making a copy of your production to a development instance and give it a go there.