This is happening again for me with 6.0.7, except a variation of the last error (column 'permanent' rather than 'id'). Same solution fixed the issue but figured I'd post it in case it was a bug.
Error message
MysqlError: Duplicate column name 'permanent'
Sample stack trace
…ery called at /data/home/mysite.com/httpdocs/wp-content/db.php (777)
…/mysite.com/httpdocs/wp-content/plugins/wordfence/lib/wfDB.php (30)
in wfDB::queryWrite called at ? (?)
…/mysite.com/httpdocs/wp-content/plugins/wordfence/lib/wfDB.php (50)
…mysite.com/httpdocs/wp-content/plugins/wordfence/lib/wordfenceClass.php (333)
…mysite.com/httpdocs/wp-content/plugins/wordfence/lib/wordfenceClass.php (455)
…mysite.com/httpdocs/wp-content/plugins/wordfence/wordfence.php (25)
…_once called at /data/home/mysite.com/httpdocs/wp-settings.php (215)
…re_once called at /data/home/mysite.com/httpdocs/wp-config.php (125)
…uire_once called at /data/home/mysite.com/httpdocs/wp-load.php (37)
…ce called at /data/home/mysite.com/httpdocs/wp-blog-header.php (12)
in require called at /data/home/mysite.com/httpdocs/index.php (17)