Version 18.1 is around the corner. Please be a bit more patient and try later then when it's released. Also make sure when you run the installer there are no "duplicate" or "already exists" SQL errors when doing the database upgrade.
Register at tiki.org and you'll be able to use the account at any *.tiki.org site, thanks to the InterTiki feature. A valid email address is required to receive site notifications and occasional newsletters. You can opt out of these items at any time.
;){kind=link}