Thread:Project:Support desk/upgrade problems: 1.11 -- 1.21/reply

There are quite some results when I search for that error message with a search engine on the internet, e.g. http://www.mediawiki.org/wiki/Thread:Project:Support_desk/Database_error:_%221054:_Unknown_column_%27rev_sha1%27_in_%27field_list%27_%28localhost%29%22 and https://bugzilla.wikimedia.org/show_bug.cgi?id=34310