Just had the same problem and found the fix. The problem is the #__usergroups` didn't get created during the install. I had to revert back to the original joomla script: Don't forget to replace #_ with your prefix eg. jos_usergroups
DROP TABLE IF EXISTS `#_usergroups`; CREATE TABLE IF NOT EXISTS `#_usergroups` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'Primary Key', `parent_id` int(10) unsigned NOT NULL DEFAULT '0' COMMENT 'Adjacency List Reference Id', `lft` int(11) NOT NULL DEFAULT '0' COMMENT 'Nested set lft.', `rgt` int(11) NOT NULL DEFAULT '0' COMMENT 'Nested set rgt.', `title` varchar(100) NOT NULL DEFAULT '', PRIMARY KEY (`id`), UNIQUE KEY `idx_usergroup_parent_title_lookup` (`parent_id`,`title`), KEY `idx_usergroup_title_lookup` (`title`), KEY `idx_usergroup_adjacency_lookup` (`parent_id`), KEY `idx_usergroup_nested_set_lookup` USING BTREE (`lft`,`rgt`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=13 ; -- -- Dumping data for table `#__usergroups` --
INSERT INTO `#_usergroups` (`id`, `parent_id`, `lft`, `rgt`, `title`) VALUES (1, 0, 1, 20, 'Public'), (2, 1, 6, 17, 'Registered'), (3, 2, 7, 14, 'Author'), (4, 3, 8, 11, 'Editor'), (5, 4, 9, 10, 'Publisher'), (6, 1, 2, 5, 'Manager'), (7, 6, 3, 4, 'Administrator'), (8, 1, 18, 19, 'Super Users'), (12, 2, 15, 16, 'Customer Group (Example)'), (10, 3, 12, 13, 'Shop Suppliers (Example)');