The only 'non-standard' thing that I am doing, is ticking the box 'Have you manually modified FUDforum's SQL structure? (leave unchecked if unsure)' because I have added a couple of columns to fud_users.
Next:
Fatal error: Uncaught exception 'Exception' with message '1068: Multiple primary key defined @ ALTER IGNORE TABLE fud_bookmarks ADD PRIMARY KEY (user_id,thread_id)' in /usr/www/users/myname/web/nvug/forum/upgrade.php:99 Stack trace: #0 /usr/www/users/myname/web/nvug/FUDforum/sql/mysql/db.inc(75): fud_sql_error_handler('ALTER IGNORE TA...', 'Multiple primar...', 1068, '5.0.45-log') #1 /usr/www/users/myname/web/nvug/FUDforum/include/dbadmin.inc(225): q('ALTER IGNORE TA...') #2 /usr/www/users/myname/web/nvug/forum/upgrade.php(911): create_primary_key('fud_bookmarks', 'user_id,thread_...') #3 {main} thrown in /usr/www/users/myname/web/nvug/forum/upgrade.php on line 99