[horde] imp login not working

[Kevin Smith]

This is my first experience with Horde 5, coming from v4, and I've been
fighting with Horde 5.0.1, all day; I can't get it to login... I keep
getting the error:

EMERG: HORDE User is not authorized for horde

but it seems to be logging in, with dovecot.

imap-login: Info: Login: user=<christopher>, method=PLAIN,
rip=192.168.15.49, lip=192.168.15.4, mpid=10219

auth: Debug: client out: OK    1    user=christopher

Backends.conf:

$servers['imap'] = array(
    // ENABLED by default
    'disabled' => false,
    'name' => 'IMAP Server',
    'hostspec' => '192.168.15.4',
    'hordeauth' => false,
    'protocol' => 'imap',
    'port' => 143,
    // Plaintext logins are disabled by default on IMAP servers (see RFC
3501
    // [6.2.3]), so TLS is the only guaranteed authentication available by
    // default.
    'secure' => false,
    'maildomain' => '',
    'smtp' => array(
    //    'auth' => true,
    //    'localhost' => 'localhost',
    //    'host' => 'smtp.example.com',
    //    'password' => null,
    //    'port' => 25,
    //    'username' => null
    ),
    'cache' => false,
);

conf.php

$conf['vhosts'] = false;
$conf['debug_level'] = E_ALL & ~E_NOTICE;
$conf['max_exec_time'] = 0;
$conf['compress_pages'] = true;
$conf['secret_key'] = '50a31912-49b4-4c59-9a86-4ebbc0a80f04';
$conf['umask'] = 077;
$conf['testdisable'] = true;
$conf['use_ssl'] = 2;
$conf['server']['name'] = $_SERVER['SERVER_NAME'];
$conf['urls']['token_lifetime'] = 30;
$conf['urls']['hmac_lifetime'] = 30;
$conf['urls']['pretty'] = false;
$conf['safe_ips'] = array();
$conf['session']['name'] = 'Horde';
$conf['session']['use_only_cookies'] = true;
$conf['session']['cache_limiter'] = 'nocache';
$conf['session']['timeout'] = 0;
$conf['session']['max_time'] = 0;
$conf['cookie']['domain'] = $_SERVER['SERVER_NAME'];
$conf['cookie']['path'] = '/';
$conf['sql']['username'] = 'root';
$conf['sql']['password'] = 'Zebra123';
$conf['sql']['hostspec'] = 'localhost';
$conf['sql']['port'] = 3306;
$conf['sql']['protocol'] = 'tcp';
$conf['sql']['database'] = 'horde';
$conf['sql']['charset'] = 'utf-8';
$conf['sql']['ssl'] = false;
$conf['sql']['splitread'] = false;
$conf['sql']['phptype'] = 'mysqli';
$conf['ldap']['useldap'] = false;
$conf['auth']['admins'] = array('Administrator', 'christopher');
$conf['auth']['checkip'] = true;
$conf['auth']['checkbrowser'] = true;
$conf['auth']['resetpassword'] = true;
$conf['auth']['alternate_login'] = false;
$conf['auth']['redirect_on_logout'] = false;
$conf['auth']['list_users'] = 'list';
$conf['auth']['params']['app'] = 'imp';
$conf['auth']['driver'] = 'application';
$conf['auth']['params']['count_bad_logins'] = false;
$conf['auth']['params']['login_block'] = false;
$conf['auth']['params']['login_block_count'] = 5;
$conf['auth']['params']['login_block_time'] = 5;
$conf['signup']['allow'] = false;
$conf['log']['priority'] = 'DEBUG';
$conf['log']['ident'] = 'HORDE';
$conf['log']['name'] = '/var/log/horde.log';
$conf['log']['params']['append'] = true;
$conf['log']['params']['format'] = 'default';
$conf['log']['type'] = 'file';
$conf['log']['enabled'] = true;
$conf['log_accesskeys'] = false;
$conf['prefs']['params']['driverconfig'] = 'horde';
$conf['prefs']['driver'] = 'Sql';
$conf['alarms']['params']['driverconfig'] = 'horde';
$conf['alarms']['params']['ttl'] = 300;
$conf['alarms']['driver'] = 'Sql';
$conf['group']['driverconfig'] = 'horde';
$conf['group']['driver'] = 'Sql';
$conf['perms']['driverconfig'] = 'horde';
$conf['perms']['driver'] = 'Sql';
$conf['share']['no_sharing'] = false;
$conf['share']['auto_create'] = true;
$conf['share']['world'] = true;
$conf['share']['any_group'] = false;
$conf['share']['hidden'] = false;
$conf['share']['cache'] = false;
$conf['share']['driver'] = 'Sqlng';
$conf['cache']['default_lifetime'] = 86400;
$conf['cache']['params']['sub'] = 0;
$conf['cache']['driver'] = 'File';
$conf['cache']['compress'] = true;
$conf['cache']['use_memorycache'] = '';
$conf['cachecssparams']['url_version_param'] = true;
$conf['cachecss'] = false;
$conf['cachejsparams']['url_version_param'] = true;
$conf['cachejs'] = false;
$conf['cachethemes'] = false;
$conf['lock']['params']['driverconfig'] = 'horde';
$conf['lock']['driver'] = 'Sql';
$conf['token']['params']['driverconfig'] = 'horde';
$conf['token']['driver'] = 'Sql';
$conf['mailer']['params']['sendmail_path'] = '/usr/lib/sendmail';
$conf['mailer']['params']['sendmail_args'] = '-oi';
$conf['mailer']['type'] = 'sendmail';
$conf['mailformat']['brokenrfc2231'] = false;
$conf['vfs']['params']['driverconfig'] = 'horde';
$conf['vfs']['type'] = 'Sql';
$conf['sessionhandler']['type'] = 'Builtin';
$conf['sessionhandler']['memcache'] = false;
$conf['spell']['driver'] = '';
$conf['gnupg']['keyserver'] = array('pool.sks-keyservers.net');
$conf['gnupg']['timeout'] = 10;
$conf['nobase64_img'] = false;
$conf['image']['driver'] = false;
$conf['exif']['driver'] = 'Bundled';
$conf['timezone']['location'] = 'ftp://ftp.iana.org/tz/tzdata-latest.tar.gz
';
$conf['problems']['email'] = 'webmaster at example.com';
$conf['problems']['maildomain'] = 'example.com';
$conf['problems']['tickets'] = false;
$conf['problems']['attachments'] = true;
$conf['menu']['links']['help'] = 'all';
$conf['menu']['links']['prefs'] = 'authenticated';
$conf['menu']['links']['problem'] = 'all';
$conf['menu']['links']['login'] = 'all';
$conf['menu']['links']['logout'] = 'authenticated';
$conf['portal']['fixed_blocks'] = array();
$conf['accounts']['driver'] = 'null';
$conf['user']['verify_from_addr'] = false;
$conf['user']['select_view'] = true;
$conf['facebook']['enabled'] = false;
$conf['twitter']['enabled'] = false;
$conf['urlshortener'] = false;
$conf['weather']['provider'] = false;
$conf['imap']['enabled'] = false;
$conf['imsp']['enabled'] = false;
$conf['kolab']['enabled'] = false;
$conf['memcache']['enabled'] = false;
$conf['activesync']['enabled'] = false;

What am I missing?