Gareth,

I took a look at the UpgradeToVersion614 method's source code. It only processes SuperUser accounts (host by default) and then only to set the membrship UpdatePassword flag to false so as not to force the host user to change their default password upon the first login. Most likely the host account's password format was invalid and should be changed.

However, if the failure of the upgrade at this point caused the installation of updated modules and providers to fail to occur, the site may have been left in an "in between state" in which case it may be best to restore the site files and database from a backup taken before the upgrade, fix the invalid email address(es) for the SuperUser account(s), and re-do the upgrade. At the leaset I would check that the Html module and the RadEditorProvider (both of which had new upgraded in 6.1.4) were successfully upgraded to the versions included in the upgrade package. You should be able to check that on the Host --> Extensions page.