"HostId is not registered" when starting User Profile Synchronization Service

Question

I'm totally stuck trying to get the User Profile Synchronization Service to run in a new SharePoint 2013 system. I've followed every possible guide and applied every known fix, but it's still unable to start. I really don't know what else to do.

Environment:

• Single Active Directory domain; the NetBIOS name matches the first part of the domain FQDN.
• Test system: a single server running Windows Server 2012, SQL Server 2012, SharePoint 2013.
• WS 2012 is updated to latest patches; all system prerequisites are in place; SQL Server 2012 is updated to SP1; SP2013 is updated with the March 2013 update.
• SharePoint is configured to connect to the DB using the NetBIOS name of the server (NOT the FQDN); WINS is operational in the network.
• SharePoint is up and running, I can create and browse sites.
• The User Profile Service is also up and running; MySites works fine.
• The farm administrator account is in the local Administrators group on the test system.
• Network DTC access is enabled.

When I try to start the UPSS, it doesn't work. The main (repeated) error in the event log is the dreaded .Net SqlClient Data Provider: System.Data.SqlClient.SqlException: HostId is not registered.

What I tried:

• Of course, I followed http://www.harbar.net/articles/sp2010ups.aspx.
• I restarted IIS and/or the whole server countless times.
• I rebuilt the server from scratch several times.
• I tried setting up SharePoint with or without using the Farm Configuration Wizard. No changes.
• I deleted and recreated the User Profile Service Application various times. No changes.
• I installed SP2013 with or without the March 2013 update. No changes.
• I tried adding the farm account to the Domain Admins group, as per Forefront Identity Manager errors when starting the SharePoint 2010 User Profile Synchronization Service Application. No changes.
• I cleared the SP cache and the certificate store, as per http://chrishattonnzlsp.wordpress.com/2010/11/30/hostid-is-not-registered-forefront-identity-manager. No changes.
• I verified the proxy settings for the farm account and for the system (netsh winhttp); no proxy in use anywhere. I even checked the proxy logs, there are no connections at all from the SP server when the UPSS is trying to start.

I'm really stuck and don't know what else to do.

Answer 1

Ok, I know this sounds completely crazy, but here it is: in order for the UPSS to be provisioned and start working, I had to configure the farm service account to have English regional settings.

The server is an English edition of Windows Server 2012, with an English installation of SharePoint 2013 and its Italian language pack; and, since the server is actually in Italy, the default regional settings are set to Italian, and thus the regional settings for all new user profiles are set to Italian; this includes, of course, the farm service account.

This is enough for the UPSS to painfully crash with that totally unrelated "HostId is not registered" error.

I don't know if the actual requirement is "the farm service account should have regional settings matching the O.S. language", or "the farm service account should have regional settings matching the installed SharePoint edition", or even "the farm service account should have English regional settings and will not work with anything else".

What I know is, this is completely crazy, absolutely undocumented, and definitely the sort of behaviour an expensive software released in the year 2013 with f**cking built-in multi-language support really can't afford to exhibit.