Thread:Project:Support desk/upgrade from 1.16.1 to 1.21.1 failing

I am struggling to upgrade from 1.16.1 to 1.21.1. This is a private wiki so I can't give a URL.

Before doing this I made a copy of the wiki on a local PC and upgraded all extensions until I had a correctly working 1.21.1 installation. I then copied the directory tree to the server as 'w.1.12.1', backed up my DB, renamed my 'w' to 'w.16.1', renamed 'w.1.12.1' to 'w', and edited my .htaccess files to disable mod_rewrite.

Attempting to upgrade via the web interface failed with a reference to iocube.so, which the hosting provider says they don't believe is the problem. After restoring my backed up DB, I asked them to run update.php for me, and this is what they got:

$ php /home/vigilhealth/www/www/w/maintenance/update.php A database error has occurred. Did you forget to run maintenance/update.php after upgrading? See: https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script Query: SELECT page_id,page_len,page_is_redirect,page_latest,page_content_model  FROM `page`  WHERE page_namespace = '10' AND page_title = 'Extension_DPL'  LIMIT 1 Function: LinkCache::addLinkObj Error: 1054 Unknown column 'page_content_model' in 'field list' (localhost:/tmp/mysql5.sock)

I'm not sure where to go from here. Unless there was some unknown problem with the DB restore, this is the DB that was working correctly with 1.16.1, so why is update.php failing? (Yes, I am using DPL, but why should that be a page title?)

Any help appreciated.